20631897 has 96 divisors (see below), whose sum is σ = 39626496. Its totient is φ = 10137600.

The previous prime is 20631869. The next prime is 20631899. The reversal of 20631897 is 79813602.

It is not a de Polignac number, because 20631897 - 2⁸ = 20631641 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20631899) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 503197 + ... + 503237.

It is an arithmetic number, because the mean of its divisors is an integer number (412776).

Almost surely, 2^20631897 is an apocalyptic number.

It is an amenable number.

20631897 is a deficient number, since it is larger than the sum of its proper divisors (18994599).

20631897 is a wasteful number, since it uses less digits than its factorization.

20631897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111 (or 108 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 20631897 is about 4542.2348023853. The cubic root of 20631897 is about 274.2708928701.

It can be divided in two parts, 20631 and 897, that added together give a triangular number (21528 = T₂₀₇).

The spelling of 20631897 in words is "twenty million, six hundred thirty-one thousand, eight hundred ninety-seven".