21463957 has 4 divisors (see below), whose sum is σ = 21627936. Its totient is φ = 21299980.

The previous prime is 21463943. The next prime is 21463961. The reversal of 21463957 is 75936412.

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 a de Polignac number, because none of the positive numbers 2^k-21463957 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21466957) 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, 81793 + ... + 82054.

It is an arithmetic number, because the mean of its divisors is an integer number (5406984).

Almost surely, 2^21463957 is an apocalyptic number.

It is an amenable number.

21463957 is a deficient number, since it is larger than the sum of its proper divisors (163979).

21463957 is a wasteful number, since it uses less digits than its factorization.

21463957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163978.

The product of its digits is 45360, while the sum is 37.

The square root of 21463957 is about 4632.9210008374. The cubic root of 21463957 is about 277.9094170313.

The spelling of 21463957 in words is "twenty-one million, four hundred sixty-three thousand, nine hundred fifty-seven".