21369755424 has 48 divisors (see below), whose sum is σ = 56523852000. Its totient is φ = 7068871680.

The previous prime is 21369755417. The next prime is 21369755431. The reversal of 21369755424 is 42455796312.

It is an interprime number because it is at equal distance from previous prime (21369755417) and next prime (21369755431).

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (48).

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, 837049 + ... + 862200.

It is an arithmetic number, because the mean of its divisors is an integer number (1177580250).

Almost surely, 2^21369755424 is an apocalyptic number.

21369755424 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21369755424 is an abundant number, since it is smaller than the sum of its proper divisors (35154096576).

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

21369755424 is a wasteful number, since it uses less digits than its factorization.

21369755424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1699393 (or 1699385 counting only the distinct ones).

The product of its digits is 1814400, while the sum is 48.

The spelling of 21369755424 in words is "twenty-one billion, three hundred sixty-nine million, seven hundred fifty-five thousand, four hundred twenty-four".