21213606736 has 20 divisors (see below), whose sum is σ = 46972986592. Its totient is φ = 9091545696.

The previous prime is 21213606731. The next prime is 21213606737. The reversal of 21213606736 is 63760631212.

It is a super-2 number, since 2×21213606736² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21213606695 and 21213606704.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21213606731) 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, 94703490 + ... + 94703713.

Almost surely, 2^21213606736 is an apocalyptic number.

It is an amenable number.

21213606736 is an abundant number, since it is smaller than the sum of its proper divisors (25759379856).

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

21213606736 is a wasteful number, since it uses less digits than its factorization.

21213606736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 189407218 (or 189407212 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 37.

The spelling of 21213606736 in words is "twenty-one billion, two hundred thirteen million, six hundred six thousand, seven hundred thirty-six".