21729096 has 24 divisors (see below), whose sum is σ = 58849830. Its totient is φ = 7243008.

The previous prime is 21729079. The next prime is 21729119. The reversal of 21729096 is 69092712.

It can be written as a sum of positive squares in only one way, i.e., 16112196 + 5616900 = 4014^2 + 2370^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is a super-2 number, since 2×21729096² = 944307225954432, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21729096.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 150825 + ... + 150968.

Almost surely, 2^21729096 is an apocalyptic number.

It is an amenable number.

21729096 is an abundant number, since it is smaller than the sum of its proper divisors (37120734).

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

21729096 is a wasteful number, since it uses less digits than its factorization.

21729096 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 301805 (or 301798 counting only the distinct ones).

The product of its (nonzero) digits is 13608, while the sum is 36.

The square root of 21729096 is about 4661.4478437498. The cubic root of 21729096 is about 279.0490529237.

The spelling of 21729096 in words is "twenty-one million, seven hundred twenty-nine thousand, ninety-six".