21862864 has 40 divisors (see below), whose sum is σ = 43559712. Its totient is φ = 10627200.

The previous prime is 21862861. The next prime is 21862873. The reversal of 21862864 is 46826812.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21862861) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 134047 + ... + 134209.

Almost surely, 2^21862864 is an apocalyptic number.

It is an amenable number.

21862864 is a deficient number, since it is larger than the sum of its proper divisors (21696848).

21862864 is a wasteful number, since it uses less digits than its factorization.

21862864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 355 (or 349 counting only the distinct ones).

The product of its digits is 36864, while the sum is 37.

The square root of 21862864 is about 4675.7741605001. The cubic root of 21862864 is about 279.6205062996.

It can be divided in two parts, 2186 and 2864, that added together give a triangular number (5050 = T₁₀₀).

The spelling of 21862864 in words is "twenty-one million, eight hundred sixty-two thousand, eight hundred sixty-four".