61500820 has 48 divisors (see below), whose sum is σ = 133358400. Its totient is φ = 23809280.

The previous prime is 61500811. The next prime is 61500823. The reversal of 61500820 is 2800516.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 61500791 and 61500800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61500823) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 146571 + ... + 146989.

It is an arithmetic number, because the mean of its divisors is an integer number (2778300).

Almost surely, 2^61500820 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61500820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (66679200).

61500820 is an abundant number, since it is smaller than the sum of its proper divisors (71857580).

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

61500820 is a wasteful number, since it uses less digits than its factorization.

61500820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 648 (or 646 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 61500820 is about 7842.2458517953. The cubic root of 61500820 is about 394.7240929621.

The spelling of 61500820 in words is "sixty-one million, five hundred thousand, eight hundred twenty".