61721265730 has 32 divisors (see below), whose sum is σ = 123824712960. Its totient is φ = 22013280000.

The previous prime is 61721265721. The next prime is 61721265731. The reversal of 61721265730 is 3756212716.

It is not an unprimeable number, because it can be changed into a prime (61721265731) 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, 9551146 + ... + 9557605.

It is an arithmetic number, because the mean of its divisors is an integer number (3869522280).

Almost surely, 2^61721265730 is an apocalyptic number.

61721265730 is an abundant number, since it is smaller than the sum of its proper divisors (62103447230).

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

61721265730 is a wasteful number, since it uses less digits than its factorization.

61721265730 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19108794.

The product of its (nonzero) digits is 105840, while the sum is 40.

The spelling of 61721265730 in words is "sixty-one billion, seven hundred twenty-one million, two hundred sixty-five thousand, seven hundred thirty".