15997000681 has 4 divisors (see below), whose sum is σ = 15997637700. Its totient is φ = 15996363664.

The previous prime is 15997000609. The next prime is 15997000703. The reversal of 15997000681 is 18600079951.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 12593328400 + 3403672281 = 112220^2 + 58341^2 .

It is a cyclic number.

It is not a de Polignac number, because 15997000681 - 2⁷ = 15997000553 is a prime.

It is a super-2 number, since 2×15997000681² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15997400681) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 279226 + ... + 331603.

It is an arithmetic number, because the mean of its divisors is an integer number (3999409425).

Almost surely, 2^15997000681 is an apocalyptic number.

It is an amenable number.

15997000681 is a deficient number, since it is larger than the sum of its proper divisors (637019).

15997000681 is an equidigital number, since it uses as much as digits as its factorization.

15997000681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 637018.

The product of its (nonzero) digits is 136080, while the sum is 46.

The spelling of 15997000681 in words is "fifteen billion, nine hundred ninety-seven million, six hundred eighty-one", and thus it is an aban number.