21277724072 has 16 divisors (see below), whose sum is σ = 43522617600. Its totient is φ = 9671692720.

The previous prime is 21277724071. The next prime is 21277724087. The reversal of 21277724072 is 27042777212.

It is a super-2 number, since 2×21277724072² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21277724071) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 120896072 + ... + 120896247.

It is an arithmetic number, because the mean of its divisors is an integer number (2720163600).

Almost surely, 2^21277724072 is an apocalyptic number.

21277724072 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21277724072 is an abundant number, since it is smaller than the sum of its proper divisors (22244893528).

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

21277724072 is a wasteful number, since it uses less digits than its factorization.

21277724072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 241792336 (or 241792332 counting only the distinct ones).

The product of its (nonzero) digits is 153664, while the sum is 41.

The spelling of 21277724072 in words is "twenty-one billion, two hundred seventy-seven million, seven hundred twenty-four thousand, seventy-two".