65721136 has 20 divisors (see below), whose sum is σ = 137130112. Its totient is φ = 30332736.

The previous prime is 65721121. The next prime is 65721169. The reversal of 65721136 is 63112756.

It is a junction number, because it is equal to n+sod(n) for n = 65721098 and 65721107.

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, 157776 + ... + 158191.

Almost surely, 2^65721136 is an apocalyptic number.

It is an amenable number.

65721136 is an abundant number, since it is smaller than the sum of its proper divisors (71408976).

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

65721136 is a wasteful number, since it uses less digits than its factorization.

65721136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 315988 (or 315982 counting only the distinct ones).

The product of its digits is 7560, while the sum is 31.

The square root of 65721136 is about 8106.8573442488. The cubic root of 65721136 is about 403.5540286767.

The spelling of 65721136 in words is "sixty-five million, seven hundred twenty-one thousand, one hundred thirty-six".