37649681 has 2 divisors, whose sum is σ = 37649682. Its totient is φ = 37649680.

The previous prime is 37649671. The next prime is 37649687. The reversal of 37649681 is 18694673.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 32433025 + 5216656 = 5695^2 + 2284^2 .

It is a cyclic number.

It is not a de Polignac number, because 37649681 - 2⁶ = 37649617 is a prime.

It is a super-2 number, since 2×37649681² = 2834996958803522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (37649687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 18824840 + 18824841.

It is an arithmetic number, because the mean of its divisors is an integer number (18824841).

Almost surely, 2^37649681 is an apocalyptic number.

It is an amenable number.

37649681 is a deficient number, since it is larger than the sum of its proper divisors (1).

37649681 is an equidigital number, since it uses as much as digits as its factorization.

37649681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 217728, while the sum is 44.

The square root of 37649681 is about 6135.9335882977. The cubic root of 37649681 is about 335.1612233545.

The spelling of 37649681 in words is "thirty-seven million, six hundred forty-nine thousand, six hundred eighty-one".