21275588 has 6 divisors (see below), whose sum is σ = 37232286. Its totient is φ = 10637792.

The previous prime is 21275587. The next prime is 21275599. The reversal of 21275588 is 88557212.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 13778944 + 7496644 = 3712^2 + 2738^2 .

It is not an unprimeable number, because it can be changed into a prime (21275587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2659445 + ... + 2659452.

It is an arithmetic number, because the mean of its divisors is an integer number (6205381).

Almost surely, 2^21275588 is an apocalyptic number.

It is an amenable number.

21275588 is a deficient number, since it is larger than the sum of its proper divisors (15956698).

21275588 is a wasteful number, since it uses less digits than its factorization.

21275588 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5318901 (or 5318899 counting only the distinct ones).

The product of its digits is 44800, while the sum is 38.

The square root of 21275588 is about 4612.5468019306. The cubic root of 21275588 is about 277.0940437541.

The spelling of 21275588 in words is "twenty-one million, two hundred seventy-five thousand, five hundred eighty-eight".