21551132 has 6 divisors (see below), whose sum is σ = 37714488. Its totient is φ = 10775564.

The previous prime is 21551119. The next prime is 21551137. The reversal of 21551132 is 23115512.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21551137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2693888 + ... + 2693895.

It is an arithmetic number, because the mean of its divisors is an integer number (6285748).

Almost surely, 2^21551132 is an apocalyptic number.

It is an amenable number.

21551132 is a deficient number, since it is larger than the sum of its proper divisors (16163356).

21551132 is a wasteful number, since it uses less digits than its factorization.

21551132 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5387787 (or 5387785 counting only the distinct ones).

The product of its digits is 300, while the sum is 20.

The square root of 21551132 is about 4642.3196787813. The cubic root of 21551132 is about 278.2851481321.

Adding to 21551132 its reverse (23115512), we get a palindrome (44666644).

The spelling of 21551132 in words is "twenty-one million, five hundred fifty-one thousand, one hundred thirty-two".