72661987 has 2 divisors, whose sum is σ = 72661988. Its totient is φ = 72661986.

The previous prime is 72661973. The next prime is 72661997. The reversal of 72661987 is 78916627.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72661987 is a prime.

It is not a weakly prime, because it can be changed into another prime (72661957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36330993 + 36330994.

It is an arithmetic number, because the mean of its divisors is an integer number (36330994).

Almost surely, 2^72661987 is an apocalyptic number.

72661987 is a deficient number, since it is larger than the sum of its proper divisors (1).

72661987 is an equidigital number, since it uses as much as digits as its factorization.

72661987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 254016, while the sum is 46.

The square root of 72661987 is about 8524.2000797729. The cubic root of 72661987 is about 417.2878662242.

The spelling of 72661987 in words is "seventy-two million, six hundred sixty-one thousand, nine hundred eighty-seven".