21431158 has 16 divisors (see below), whose sum is σ = 36817920. Its totient is φ = 9165096.

The previous prime is 21431149. The next prime is 21431161. The reversal of 21431158 is 85113412.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6523 + ... + 9241.

It is an arithmetic number, because the mean of its divisors is an integer number (2301120).

Almost surely, 2^21431158 is an apocalyptic number.

21431158 is a deficient number, since it is larger than the sum of its proper divisors (15386762).

21431158 is a wasteful number, since it uses less digits than its factorization.

21431158 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3291.

The product of its digits is 960, while the sum is 25.

The square root of 21431158 is about 4629.3798720779. The cubic root of 21431158 is about 277.7677873859.

It can be divided in two parts, 214311 and 58, that added together give a square (214369 = 463²).

The spelling of 21431158 in words is "twenty-one million, four hundred thirty-one thousand, one hundred fifty-eight".