21487010 has 16 divisors (see below), whose sum is σ = 39722616. Its totient is φ = 8362368.

The previous prime is 21487009. The next prime is 21487051. The reversal of 21487010 is 1078412.

It can be written as a sum of positive squares in 4 ways, for example, as 16072081 + 5414929 = 4009^2 + 2327^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28667 + ... + 29406.

Almost surely, 2^21487010 is an apocalyptic number.

21487010 is a deficient number, since it is larger than the sum of its proper divisors (18235606).

21487010 is a wasteful number, since it uses less digits than its factorization.

21487010 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58117.

The product of its (nonzero) digits is 448, while the sum is 23.

The square root of 21487010 is about 4635.4082883819. The cubic root of 21487010 is about 278.0088760688.

The spelling of 21487010 in words is "twenty-one million, four hundred eighty-seven thousand, ten".