21132742 has 8 divisors (see below), whose sum is σ = 31811976. Its totient is φ = 10528752.

The previous prime is 21132739. The next prime is 21132757. The reversal of 21132742 is 24723112.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18103 + ... + 19234.

It is an arithmetic number, because the mean of its divisors is an integer number (3976497).

Almost surely, 2^21132742 is an apocalyptic number.

21132742 is a deficient number, since it is larger than the sum of its proper divisors (10679234).

21132742 is a wasteful number, since it uses less digits than its factorization.

21132742 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37622.

The product of its digits is 672, while the sum is 22.

The square root of 21132742 is about 4597.0362191308. The cubic root of 21132742 is about 276.4725067957.

Adding to 21132742 its reverse (24723112), we get a palindrome (45855854).

The spelling of 21132742 in words is "twenty-one million, one hundred thirty-two thousand, seven hundred forty-two".