72129977 has 2 divisors, whose sum is σ = 72129978. Its totient is φ = 72129976.

The previous prime is 72129971. The next prime is 72130021. The reversal of 72129977 is 77992127.

It is an a-pointer prime, because the next prime (72130021) can be obtained adding 72129977 to its sum of digits (44).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 41615401 + 30514576 = 6451^2 + 5524^2 .

It is a cyclic number.

It is not a de Polignac number, because 72129977 - 2²⁰ = 71081401 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (72129971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36064988 + 36064989.

It is an arithmetic number, because the mean of its divisors is an integer number (36064989).

Almost surely, 2^72129977 is an apocalyptic number.

It is an amenable number.

72129977 is a deficient number, since it is larger than the sum of its proper divisors (1).

72129977 is an equidigital number, since it uses as much as digits as its factorization.

72129977 is an evil number, because the sum of its binary digits is even.

The product of its digits is 111132, while the sum is 44.

The square root of 72129977 is about 8492.9368889684. The cubic root of 72129977 is about 416.2669502848.

The spelling of 72129977 in words is "seventy-two million, one hundred twenty-nine thousand, nine hundred seventy-seven".