21777649436 has 12 divisors (see below), whose sum is σ = 38118760680. Its totient is φ = 10886574960.

The previous prime is 21777649427. The next prime is 21777649457. The reversal of 21777649436 is 63494677712.

It is a super-2 number, since 2×21777649436² (a number of 21 digits) contains 22 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, 540566 + ... + 579453.

It is an arithmetic number, because the mean of its divisors is an integer number (3176563390).

Almost surely, 2^21777649436 is an apocalyptic number.

It is an amenable number.

21777649436 is a deficient number, since it is larger than the sum of its proper divisors (16341111244).

21777649436 is a wasteful number, since it uses less digits than its factorization.

21777649436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1124884 (or 1124882 counting only the distinct ones).

The product of its digits is 10668672, while the sum is 56.

The spelling of 21777649436 in words is "twenty-one billion, seven hundred seventy-seven million, six hundred forty-nine thousand, four hundred thirty-six".