97720919015 has 4 divisors (see below), whose sum is σ = 117265102824. Its totient is φ = 78176735208.

The previous prime is 97720918991. The next prime is 97720919033. The reversal of 97720919015 is 51091902779.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 97720919015 - 2⁸ = 97720918759 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9772091897 + ... + 9772091906.

It is an arithmetic number, because the mean of its divisors is an integer number (29316275706).

Almost surely, 2^97720919015 is an apocalyptic number.

97720919015 is a deficient number, since it is larger than the sum of its proper divisors (19544183809).

97720919015 is a wasteful number, since it uses less digits than its factorization.

97720919015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19544183808.

The product of its (nonzero) digits is 357210, while the sum is 50.

The spelling of 97720919015 in words is "ninety-seven billion, seven hundred twenty million, nine hundred nineteen thousand, fifteen".