21132137 has 8 divisors (see below), whose sum is σ = 22813896. Its totient is φ = 19458432.

The previous prime is 21132131. The next prime is 21132191. The reversal of 21132137 is 73123112.

It can be written as a sum of positive squares in 4 ways, for example, as 737881 + 20394256 = 859^2 + 4516^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21132137 - 2⁸ = 21131881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21132131) 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, 4163 + ... + 7719.

It is an arithmetic number, because the mean of its divisors is an integer number (2851737).

Almost surely, 2^21132137 is an apocalyptic number.

It is an amenable number.

21132137 is a deficient number, since it is larger than the sum of its proper divisors (1681759).

21132137 is a wasteful number, since it uses less digits than its factorization.

21132137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4027.

The product of its digits is 252, while the sum is 20.

The square root of 21132137 is about 4596.9704153932. The cubic root of 21132137 is about 276.4698684338.

Adding to 21132137 its reverse (73123112), we get a palindrome (94255249).

The spelling of 21132137 in words is "twenty-one million, one hundred thirty-two thousand, one hundred thirty-seven".