997720013 has 8 divisors (see below), whose sum is σ = 1065311808. Its totient is φ = 932145984.

The previous prime is 997720007. The next prime is 997720043. The reversal of 997720013 is 310027799.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-997720013 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (997720043) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 503420 + ... + 505397.

It is an arithmetic number, because the mean of its divisors is an integer number (133163976).

Almost surely, 2^997720013 is an apocalyptic number.

It is an amenable number.

997720013 is a deficient number, since it is larger than the sum of its proper divisors (67591795).

997720013 is a wasteful number, since it uses less digits than its factorization.

997720013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1008883.

The product of its (nonzero) digits is 23814, while the sum is 38.

The square root of 997720013 is about 31586.7062702017. The cubic root of 997720013 is about 999.2394260072.

The spelling of 997720013 in words is "nine hundred ninety-seven million, seven hundred twenty thousand, thirteen".