21131642 has 24 divisors (see below), whose sum is σ = 37034496. Its totient is φ = 9016728.

The previous prime is 21131597. The next prime is 21131651. The reversal of 21131642 is 24613112.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 37253 + ... + 37815.

It is an arithmetic number, because the mean of its divisors is an integer number (1543104).

Almost surely, 2^21131642 is an apocalyptic number.

21131642 is a deficient number, since it is larger than the sum of its proper divisors (15902854).

21131642 is a wasteful number, since it uses less digits than its factorization.

21131642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 962 (or 955 counting only the distinct ones).

The product of its digits is 288, while the sum is 20.

The square root of 21131642 is about 4596.9165752709. The cubic root of 21131642 is about 276.4677097367.

Adding to 21131642 its reverse (24613112), we get a palindrome (45744754).

The spelling of 21131642 in words is "twenty-one million, one hundred thirty-one thousand, six hundred forty-two".