61612621616 has 80 divisors (see below), whose sum is σ = 146994591744. Its totient is φ = 24362249472.

The previous prime is 61612621579. The next prime is 61612621633.

It is a happy number.

61612621616 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×61612621616² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 61612621616.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3320621 + ... + 3339123.

Almost surely, 2^61612621616 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 61612621616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (73497295872).

61612621616 is an abundant number, since it is smaller than the sum of its proper divisors (85381970128).

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

61612621616 is a wasteful number, since it uses less digits than its factorization.

61612621616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20818 (or 20812 counting only the distinct ones).

The product of its digits is 31104, while the sum is 38.

The spelling of 61612621616 in words is "sixty-one billion, six hundred twelve million, six hundred twenty-one thousand, six hundred sixteen".