73661531 has 2 divisors, whose sum is σ = 73661532. Its totient is φ = 73661530.

The previous prime is 73661513. The next prime is 73661557. The reversal of 73661531 is 13516637.

Together with previous prime (73661513) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-73661531 is a prime.

It is a super-2 number, since 2×73661531² = 10852042298527922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (73661501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36830765 + 36830766.

It is an arithmetic number, because the mean of its divisors is an integer number (36830766).

Almost surely, 2^73661531 is an apocalyptic number.

73661531 is a deficient number, since it is larger than the sum of its proper divisors (1).

73661531 is an equidigital number, since it uses as much as digits as its factorization.

73661531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11340, while the sum is 32.

The square root of 73661531 is about 8582.6296086922. The cubic root of 73661531 is about 419.1925738583.

The spelling of 73661531 in words is "seventy-three million, six hundred sixty-one thousand, five hundred thirty-one".