61212388720 has 80 divisors (see below), whose sum is σ = 164941014528. Its totient is φ = 20691498240.

The previous prime is 61212388621. The next prime is 61212388723. The reversal of 61212388720 is 2788321216.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61212388723) 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, 730014 + ... + 809533.

Almost surely, 2^61212388720 is an apocalyptic number.

It is an amenable number.

61212388720 is an abundant number, since it is smaller than the sum of its proper divisors (103728625808).

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

61212388720 is a wasteful number, since it uses less digits than its factorization.

61212388720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1539638 (or 1539632 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 40.

The spelling of 61212388720 in words is "sixty-one billion, two hundred twelve million, three hundred eighty-eight thousand, seven hundred twenty".