72780091 has 2 divisors, whose sum is σ = 72780092. Its totient is φ = 72780090.

The previous prime is 72780079. The next prime is 72780121. The reversal of 72780091 is 19008727.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 72780091 - 2⁹ = 72779579 is a prime.

It is not a weakly prime, because it can be changed into another prime (72700091) 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, 36390045 + 36390046.

It is an arithmetic number, because the mean of its divisors is an integer number (36390046).

Almost surely, 2^72780091 is an apocalyptic number.

72780091 is a deficient number, since it is larger than the sum of its proper divisors (1).

72780091 is an equidigital number, since it uses as much as digits as its factorization.

72780091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7056, while the sum is 34.

The square root of 72780091 is about 8531.1248379097. The cubic root of 72780091 is about 417.5138288892.

The spelling of 72780091 in words is "seventy-two million, seven hundred eighty thousand, ninety-one".