73661681 has 2 divisors, whose sum is σ = 73661682. Its totient is φ = 73661680.

The previous prime is 73661669. The next prime is 73661699. The reversal of 73661681 is 18616637.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 59290000 + 14371681 = 7700^2 + 3791^2 .

It is a cyclic number.

It is not a de Polignac number, because 73661681 - 2²⁶ = 6552817 is a prime.

It is a super-2 number, since 2×73661681² = 10852086495491522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (73661281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36830840 + 36830841.

It is an arithmetic number, because the mean of its divisors is an integer number (36830841).

Almost surely, 2^73661681 is an apocalyptic number.

It is an amenable number.

73661681 is a deficient number, since it is larger than the sum of its proper divisors (1).

73661681 is an equidigital number, since it uses as much as digits as its factorization.

73661681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36288, while the sum is 38.

The square root of 73661681 is about 8582.6383472683. The cubic root of 73661681 is about 419.1928583978.

The spelling of 73661681 in words is "seventy-three million, six hundred sixty-one thousand, six hundred eighty-one".