21435253440 has 112 divisors (see below), whose sum is σ = 68085785088. Its totient is φ = 5713644544.

The previous prime is 21435253429. The next prime is 21435253451. The reversal of 21435253440 is 4435253412.

It is an interprime number because it is at equal distance from previous prime (21435253429) and next prime (21435253451).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4281979 + ... + 4286981.

Almost surely, 2^21435253440 is an apocalyptic number.

21435253440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21435253440 is an abundant number, since it is smaller than the sum of its proper divisors (46650531648).

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

21435253440 is a wasteful number, since it uses less digits than its factorization.

21435253440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9486 (or 9476 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 33.

The spelling of 21435253440 in words is "twenty-one billion, four hundred thirty-five million, two hundred fifty-three thousand, four hundred forty".