72078961 has 2 divisors, whose sum is σ = 72078962. Its totient is φ = 72078960.

The previous prime is 72078947. The next prime is 72078967. The reversal of 72078961 is 16987027.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 47872561 + 24206400 = 6919^2 + 4920^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72078961 is a prime.

It is not a weakly prime, because it can be changed into another prime (72078967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36039480 + 36039481.

It is an arithmetic number, because the mean of its divisors is an integer number (36039481).

Almost surely, 2^72078961 is an apocalyptic number.

It is an amenable number.

72078961 is a deficient number, since it is larger than the sum of its proper divisors (1).

72078961 is an equidigital number, since it uses as much as digits as its factorization.

72078961 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 42336, while the sum is 40.

The square root of 72078961 is about 8489.9329208186. The cubic root of 72078961 is about 416.1687882157.

The spelling of 72078961 in words is "seventy-two million, seventy-eight thousand, nine hundred sixty-one".