21140537 has 8 divisors (see below), whose sum is σ = 24419232. Its totient is φ = 18088000.

The previous prime is 21140513. The next prime is 21140549. The reversal of 21140537 is 73504112.

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

It is not a de Polignac number, because 21140537 - 2¹⁰ = 21139513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21140237) 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, 56339 + ... + 56712.

It is an arithmetic number, because the mean of its divisors is an integer number (3052404).

Almost surely, 2^21140537 is an apocalyptic number.

It is an amenable number.

21140537 is a deficient number, since it is larger than the sum of its proper divisors (3278695).

21140537 is a wasteful number, since it uses less digits than its factorization.

21140537 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113079.

The product of its (nonzero) digits is 840, while the sum is 23.

The square root of 21140537 is about 4597.8839698279. The cubic root of 21140537 is about 276.5064957321.

Adding to 21140537 its reverse (73504112), we get a palindrome (94644649).

The spelling of 21140537 in words is "twenty-one million, one hundred forty thousand, five hundred thirty-seven".