21353896 has 8 divisors (see below), whose sum is σ = 40038570. Its totient is φ = 10676944.

The previous prime is 21353879. The next prime is 21353897. The reversal of 21353896 is 69835312.

It can be written as a sum of positive squares in only one way, i.e., 18748900 + 2604996 = 4330^2 + 1614^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21353897) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1334611 + ... + 1334626.

Almost surely, 2^21353896 is an apocalyptic number.

It is an amenable number.

21353896 is a deficient number, since it is larger than the sum of its proper divisors (18684674).

21353896 is a wasteful number, since it uses less digits than its factorization.

21353896 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2669243 (or 2669239 counting only the distinct ones).

The product of its digits is 38880, while the sum is 37.

The square root of 21353896 is about 4621.0275913481. The cubic root of 21353896 is about 277.4335896055.

The spelling of 21353896 in words is "twenty-one million, three hundred fifty-three thousand, eight hundred ninety-six".