21372134 has 12 divisors (see below), whose sum is σ = 37292364. Its totient is φ = 9159444.

The previous prime is 21372133. The next prime is 21372149. The reversal of 21372134 is 43127312.

21372134 = 2310² + 2311² + ... + 2313².

It is a super-2 number, since 2×21372134² = 913536223427912, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21372133) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 108944 + ... + 109139.

It is an arithmetic number, because the mean of its divisors is an integer number (3107697).

Almost surely, 2^21372134 is an apocalyptic number.

21372134 is a deficient number, since it is larger than the sum of its proper divisors (15920230).

21372134 is a wasteful number, since it uses less digits than its factorization.

21372134 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218099 (or 218092 counting only the distinct ones).

The product of its digits is 1008, while the sum is 23.

The square root of 21372134 is about 4623.0005407744. Note that the first 3 decimals coincide. The cubic root of 21372134 is about 277.5125509027.

Adding to 21372134 its reverse (43127312), we get a palindrome (64499446).

The spelling of 21372134 in words is "twenty-one million, three hundred seventy-two thousand, one hundred thirty-four".