21596554 has 12 divisors (see below), whose sum is σ = 37683954. Its totient is φ = 9255624.

The previous prime is 21596551. The next prime is 21596573. The reversal of 21596554 is 45569512.

It can be written as a sum of positive squares in only one way, i.e., 15421329 + 6175225 = 3927^2 + 2485^2 .

It is a super-2 number, since 2×21596554² = 932822289349832, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21596551) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 110089 + ... + 110284.

Almost surely, 2^21596554 is an apocalyptic number.

21596554 is a deficient number, since it is larger than the sum of its proper divisors (16087400).

21596554 is a wasteful number, since it uses less digits than its factorization.

21596554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220389 (or 220382 counting only the distinct ones).

The product of its digits is 54000, while the sum is 37.

The square root of 21596554 is about 4647.2092700889. The cubic root of 21596554 is about 278.4805191225.

It can be divided in two parts, 215 and 96554, that added together give a palindrome (96769).

The spelling of 21596554 in words is "twenty-one million, five hundred ninety-six thousand, five hundred fifty-four".