997501681 has 8 divisors (see below), whose sum is σ = 1091620224. Its totient is φ = 903955920.

The previous prime is 997501657. The next prime is 997501709. The reversal of 997501681 is 186105799.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 997501681 - 2²⁵ = 963947249 is a prime.

It is a super-2 number, since 2×997501681² = 1990019207195651522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (997501781) 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, 139545 + ... + 146518.

It is an arithmetic number, because the mean of its divisors is an integer number (136452528).

Almost surely, 2^997501681 is an apocalyptic number.

It is an amenable number.

997501681 is a deficient number, since it is larger than the sum of its proper divisors (94118543).

997501681 is a wasteful number, since it uses less digits than its factorization.

997501681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 286391.

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

The square root of 997501681 is about 31583.2500069261. The cubic root of 997501681 is about 999.1665325250.

The spelling of 997501681 in words is "nine hundred ninety-seven million, five hundred one thousand, six hundred eighty-one".