21276401 has 16 divisors (see below), whose sum is σ = 23587200. Its totient is φ = 19100928.

The previous prime is 21276389. The next prime is 21276407. The reversal of 21276401 is 10467212.

It is not a de Polignac number, because 21276401 - 2⁶ = 21276337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21276407) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 50570 + ... + 50988.

It is an arithmetic number, because the mean of its divisors is an integer number (1474200).

Almost surely, 2^21276401 is an apocalyptic number.

It is an amenable number.

21276401 is a deficient number, since it is larger than the sum of its proper divisors (2310799).

21276401 is a wasteful number, since it uses less digits than its factorization.

21276401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 568.

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 21276401 is about 4612.6349302758. The cubic root of 21276401 is about 277.0975732231.

The spelling of 21276401 in words is "twenty-one million, two hundred seventy-six thousand, four hundred one".