21551153 has 16 divisors (see below), whose sum is σ = 23876160. Its totient is φ = 19331136.

The previous prime is 21551143. The next prime is 21551171. The reversal of 21551153 is 35115512.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21551153 - 2⁴ = 21551137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21551113) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 94826 + ... + 95052.

It is an arithmetic number, because the mean of its divisors is an integer number (1492260).

Almost surely, 2^21551153 is an apocalyptic number.

It is an amenable number.

21551153 is a deficient number, since it is larger than the sum of its proper divisors (2325007).

21551153 is a wasteful number, since it uses less digits than its factorization.

21551153 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 416.

The product of its digits is 750, while the sum is 23.

The square root of 21551153 is about 4642.3219405810. The cubic root of 21551153 is about 278.2852385216.

Adding to 21551153 its reverse (35115512), we get a palindrome (56666665).

The spelling of 21551153 in words is "twenty-one million, five hundred fifty-one thousand, one hundred fifty-three".