21613332 has 24 divisors (see below), whose sum is σ = 54310816. Its totient is φ = 6650208.

The previous prime is 21613327. The next prime is 21613349. The reversal of 21613332 is 23331612.

It is a super-2 number, since 2×21613332² = 934272240284448, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 21613299 and 21613308.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 69118 + ... + 69429.

Almost surely, 2^21613332 is an apocalyptic number.

It is an amenable number.

21613332 is an abundant number, since it is smaller than the sum of its proper divisors (32697484).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21613332 is a wasteful number, since it uses less digits than its factorization.

21613332 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138567 (or 138565 counting only the distinct ones).

The product of its digits is 648, while the sum is 21.

The square root of 21613332 is about 4649.0140890301. The cubic root of 21613332 is about 278.5526160678.

Adding to 21613332 its reverse (23331612), we get a palindrome (44944944).

It can be divided in two parts, 21613 and 332, that added together give a triangular number (21945 = T₂₀₉).

The spelling of 21613332 in words is "twenty-one million, six hundred thirteen thousand, three hundred thirty-two".