37997681 has 4 divisors (see below), whose sum is σ = 38881392. Its totient is φ = 37113972.

The previous prime is 37997671. The next prime is 37997683. The reversal of 37997681 is 18679973.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 37997681 - 2¹⁰ = 37996657 is a prime.

It is a super-2 number, since 2×37997681² = 2887647522755522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (37997683) 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, 441791 + ... + 441876.

It is an arithmetic number, because the mean of its divisors is an integer number (9720348).

Almost surely, 2^37997681 is an apocalyptic number.

It is an amenable number.

37997681 is a deficient number, since it is larger than the sum of its proper divisors (883711).

37997681 is an equidigital number, since it uses as much as digits as its factorization.

37997681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 883710.

The product of its digits is 571536, while the sum is 50.

The square root of 37997681 is about 6164.2259043614. The cubic root of 37997681 is about 336.1907015750.

The spelling of 37997681 in words is "thirty-seven million, nine hundred ninety-seven thousand, six hundred eighty-one".