20631961 has 8 divisors (see below), whose sum is σ = 23912064. Its totient is φ = 17435040.

The previous prime is 20631953. The next prime is 20631971. The reversal of 20631961 is 16913602.

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

It is not a de Polignac number, because 20631961 - 2³ = 20631953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20631911) 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 7 ways as a sum of consecutive naturals, for example, 20260 + ... + 21253.

It is an arithmetic number, because the mean of its divisors is an integer number (2989008).

Almost surely, 2^20631961 is an apocalyptic number.

It is an amenable number.

20631961 is a deficient number, since it is larger than the sum of its proper divisors (3280103).

20631961 is an equidigital number, since it uses as much as digits as its factorization.

20631961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41591.

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 20631961 is about 4542.2418473701. The cubic root of 20631961 is about 274.2711764652.

The spelling of 20631961 in words is "twenty million, six hundred thirty-one thousand, nine hundred sixty-one".