21370244720 has 80 divisors (see below), whose sum is σ = 54314202240. Its totient is φ = 7755014400.

The previous prime is 21370244677. The next prime is 21370244729. The reversal of 21370244720 is 2744207312.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21370244729) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 407351 + ... + 456809.

It is an arithmetic number, because the mean of its divisors is an integer number (678927528).

Almost surely, 2^21370244720 is an apocalyptic number.

21370244720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21370244720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27157101120).

21370244720 is an abundant number, since it is smaller than the sum of its proper divisors (32943957520).

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

21370244720 is a wasteful number, since it uses less digits than its factorization.

21370244720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49974 (or 49968 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 32.

The spelling of 21370244720 in words is "twenty-one billion, three hundred seventy million, two hundred forty-four thousand, seven hundred twenty".