73557661 has 2 divisors, whose sum is σ = 73557662. Its totient is φ = 73557660.

The previous prime is 73557619. The next prime is 73557667. The reversal of 73557661 is 16675537.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59382436 + 14175225 = 7706^2 + 3765^2 .

It is an emirp because it is prime and its reverse (16675537) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 73557661 - 2⁹ = 73557149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (73557667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36778830 + 36778831.

It is an arithmetic number, because the mean of its divisors is an integer number (36778831).

Almost surely, 2^73557661 is an apocalyptic number.

It is an amenable number.

73557661 is a deficient number, since it is larger than the sum of its proper divisors (1).

73557661 is an equidigital number, since it uses as much as digits as its factorization.

73557661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 132300, while the sum is 40.

The square root of 73557661 is about 8576.5762982673. The cubic root of 73557661 is about 418.9954469272.

The spelling of 73557661 in words is "seventy-three million, five hundred fifty-seven thousand, six hundred sixty-one".