21277213824 has 96 divisors (see below), whose sum is σ = 57463164720. Its totient is φ = 6975667200.

The previous prime is 21277213823. The next prime is 21277213829. The reversal of 21277213824 is 42831277212.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×21277213824² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21277213823) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1421419 + ... + 1436309.

Almost surely, 2^21277213824 is an apocalyptic number.

21277213824 is a gapful number since it is divisible by the number (24) 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 21277213824, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28731582360).

21277213824 is an abundant number, since it is smaller than the sum of its proper divisors (36185950896).

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

21277213824 is an equidigital number, since it uses as much as digits as its factorization.

21277213824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15030 (or 14957 counting only the distinct ones).

The product of its digits is 75264, while the sum is 39.

The spelling of 21277213824 in words is "twenty-one billion, two hundred seventy-seven million, two hundred thirteen thousand, eight hundred twenty-four".