21251153 has 24 divisors (see below), whose sum is σ = 27332640. Its totient is φ = 16336320.

The previous prime is 21251141. The next prime is 21251179. The reversal of 21251153 is 35115212.

It is a happy number.

It is not a de Polignac number, because 21251153 - 2⁴ = 21251137 is a prime.

It is a super-2 number, since 2×21251153² = 903223007658818, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21251123) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 47750 + ... + 48192.

It is an arithmetic number, because the mean of its divisors is an integer number (1138860).

Almost surely, 2^21251153 is an apocalyptic number.

It is an amenable number.

21251153 is a deficient number, since it is larger than the sum of its proper divisors (6081487).

21251153 is a wasteful number, since it uses less digits than its factorization.

21251153 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 557 (or 550 counting only the distinct ones).

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

The square root of 21251153 is about 4609.8972873590. The cubic root of 21251153 is about 276.9879223361.

Adding to 21251153 its reverse (35115212), we get a palindrome (56366365).

The spelling of 21251153 in words is "twenty-one million, two hundred fifty-one thousand, one hundred fifty-three".