61213320 has 160 divisors (see below), whose sum is σ = 235224000. Its totient is φ = 13986432.

The previous prime is 61213319. The next prime is 61213333. The reversal of 61213320 is 2331216.

61213320 is a `hidden beast` number, since 612 + 1 + 33 + 20 = 666.

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 = 61213293 and 61213302.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 21331 + ... + 24029.

It is an arithmetic number, because the mean of its divisors is an integer number (1470150).

Almost surely, 2^61213320 is an apocalyptic number.

61213320 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 61213320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (117612000).

61213320 is an abundant number, since it is smaller than the sum of its proper divisors (174010680).

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

61213320 is a wasteful number, since it uses less digits than its factorization.

61213320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2729 (or 2716 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

The square root of 61213320 is about 7823.8941710634. The cubic root of 61213320 is about 394.1080552573.

Adding to 61213320 its reverse (2331216), we get a palindrome (63544536).

The spelling of 61213320 in words is "sixty-one million, two hundred thirteen thousand, three hundred twenty".