21431374 has 16 divisors (see below), whose sum is σ = 33029136. Its totient is φ = 10425600.

The previous prime is 21431359. The next prime is 21431383. The reversal of 21431374 is 47313412.

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, 10929 + ... + 12739.

It is an arithmetic number, because the mean of its divisors is an integer number (2064321).

Almost surely, 2^21431374 is an apocalyptic number.

21431374 is a deficient number, since it is larger than the sum of its proper divisors (11597762).

21431374 is a wasteful number, since it uses less digits than its factorization.

21431374 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1971.

The product of its digits is 2016, while the sum is 25.

The square root of 21431374 is about 4629.4032012777. The cubic root of 21431374 is about 277.7687205699.

Adding to 21431374 its reverse (47313412), we get a palindrome (68744786).

The spelling of 21431374 in words is "twenty-one million, four hundred thirty-one thousand, three hundred seventy-four".