61612020 has 72 divisors (see below), whose sum is σ = 188795880. Its totient is φ = 16262400.

The previous prime is 61611959. The next prime is 61612027. The reversal of 61612020 is 2021616.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 39087504 + 22524516 = 6252^2 + 4746^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 61611984 and 61612002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61612027) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 16486 + ... + 19874.

It is an arithmetic number, because the mean of its divisors is an integer number (2622165).

Almost surely, 2^61612020 is an apocalyptic number.

61612020 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61612020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (94397940).

61612020 is an abundant number, since it is smaller than the sum of its proper divisors (127183860).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

61612020 is a wasteful number, since it uses less digits than its factorization.

61612020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3505 (or 3500 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 61612020 is about 7849.3324556933. The cubic root of 61612020 is about 394.9618507193.

Adding to 61612020 its reverse (2021616), we get a palindrome (63633636).

The spelling of 61612020 in words is "sixty-one million, six hundred twelve thousand, twenty".