21400885 has 16 divisors (see below), whose sum is σ = 28670400. Its totient is φ = 15200640.

The previous prime is 21400877. The next prime is 21400889. The reversal of 21400885 is 58800412.

It is not a de Polignac number, because 21400885 - 2³ = 21400877 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21400889) 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, 2160 + ... + 6889.

It is an arithmetic number, because the mean of its divisors is an integer number (1791900).

Almost surely, 2^21400885 is an apocalyptic number.

It is an amenable number.

21400885 is a deficient number, since it is larger than the sum of its proper divisors (7269515).

21400885 is a wasteful number, since it uses less digits than its factorization.

21400885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9108.

The product of its (nonzero) digits is 2560, while the sum is 28.

The square root of 21400885 is about 4626.1090562156. The cubic root of 21400885 is about 277.6369369872.

The spelling of 21400885 in words is "twenty-one million, four hundred thousand, eight hundred eighty-five".