37721936818 has 16 divisors (see below), whose sum is σ = 58538943000. Its totient is φ = 18209064832.

The previous prime is 37721936779. The next prime is 37721936849. The reversal of 37721936818 is 81863912773.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 25388279569 + 12333657249 = 159337^2 + 111057^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1006398 + ... + 1043206.

Almost surely, 2^37721936818 is an apocalyptic number.

37721936818 is a deficient number, since it is larger than the sum of its proper divisors (20817006182).

37721936818 is a wasteful number, since it uses less digits than its factorization.

37721936818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54509.

The product of its digits is 3048192, while the sum is 55.

The spelling of 37721936818 in words is "thirty-seven billion, seven hundred twenty-one million, nine hundred thirty-six thousand, eight hundred eighteen".