21429727277 has 64 divisors (see below), whose sum is σ = 27432000000. Its totient is φ = 16666836480.

The previous prime is 21429727273. The next prime is 21429727283. The reversal of 21429727277 is 77272792412.

It is a happy number.

It is not a de Polignac number, because 21429727277 - 2² = 21429727273 is a prime.

It is a super-2 number, since 2×21429727277² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21429727273) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 28159577 + ... + 28160337.

It is an arithmetic number, because the mean of its divisors is an integer number (428625000).

Almost surely, 2^21429727277 is an apocalyptic number.

It is an amenable number.

21429727277 is a deficient number, since it is larger than the sum of its proper divisors (6002272723).

21429727277 is a wasteful number, since it uses less digits than its factorization.

21429727277 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 979 (or 965 counting only the distinct ones).

The product of its digits is 1382976, while the sum is 50.

The spelling of 21429727277 in words is "twenty-one billion, four hundred twenty-nine million, seven hundred twenty-seven thousand, two hundred seventy-seven".