21612798 has 16 divisors (see below), whose sum is σ = 48028560. Its totient is φ = 7204248.

The previous prime is 21612769. The next prime is 21612827. The reversal of 21612798 is 89721612.

It is an interprime number because it is at equal distance from previous prime (21612769) and next prime (21612827).

It is a super-2 number, since 2×21612798² = 934226074777608, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 200065 + ... + 200172.

It is an arithmetic number, because the mean of its divisors is an integer number (3001785).

Almost surely, 2^21612798 is an apocalyptic number.

21612798 is an abundant number, since it is smaller than the sum of its proper divisors (26415762).

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

21612798 is a wasteful number, since it uses less digits than its factorization.

21612798 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 400248 (or 400242 counting only the distinct ones).

The product of its digits is 12096, while the sum is 36.

The square root of 21612798 is about 4648.9566571436. The cubic root of 21612798 is about 278.5503219850.

It can be divided in two parts, 216127 and 98, that added together give a square (216225 = 465²).

The spelling of 21612798 in words is "twenty-one million, six hundred twelve thousand, seven hundred ninety-eight".