21156966776 has 16 divisors (see below), whose sum is σ = 43275614040. Its totient is φ = 9616803040.

The previous prime is 21156966767. The next prime is 21156966793. The reversal of 21156966776 is 67766965112.

It is a super-3 number, since 3×21156966776³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 120209951 + ... + 120210126.

Almost surely, 2^21156966776 is an apocalyptic number.

It is an amenable number.

21156966776 is an abundant number, since it is smaller than the sum of its proper divisors (22118647264).

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

21156966776 is a wasteful number, since it uses less digits than its factorization.

21156966776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 240420094 (or 240420090 counting only the distinct ones).

The product of its digits is 5715360, while the sum is 56.

The spelling of 21156966776 in words is "twenty-one billion, one hundred fifty-six million, nine hundred sixty-six thousand, seven hundred seventy-six".