21292507 has 2 divisors, whose sum is σ = 21292508. Its totient is φ = 21292506.

The previous prime is 21292487. The next prime is 21292519. The reversal of 21292507 is 70529212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21292507 - 2¹⁵ = 21259739 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is not a weakly prime, because it can be changed into another prime (21292577) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10646253 + 10646254.

It is an arithmetic number, because the mean of its divisors is an integer number (10646254).

Almost surely, 2^21292507 is an apocalyptic number.

21292507 is a deficient number, since it is larger than the sum of its proper divisors (1).

21292507 is an equidigital number, since it uses as much as digits as its factorization.

21292507 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 21292507 is about 4614.3804567894. The cubic root of 21292507 is about 277.1674755194.

The spelling of 21292507 in words is "twenty-one million, two hundred ninety-two thousand, five hundred seven".