78594721 has 2 divisors, whose sum is σ = 78594722. Its totient is φ = 78594720.

The previous prime is 78594701. The next prime is 78594731. The reversal of 78594721 is 12749587.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 47458321 + 31136400 = 6889^2 + 5580^2 .

It is a cyclic number.

It is not a de Polignac number, because 78594721 - 2¹¹ = 78592673 is a prime.

It is not a weakly prime, because it can be changed into another prime (78594701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39297360 + 39297361.

It is an arithmetic number, because the mean of its divisors is an integer number (39297361).

Almost surely, 2^78594721 is an apocalyptic number.

It is an amenable number.

78594721 is a deficient number, since it is larger than the sum of its proper divisors (1).

78594721 is an equidigital number, since it uses as much as digits as its factorization.

78594721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 141120, while the sum is 43.

The square root of 78594721 is about 8865.3663770879. The cubic root of 78594721 is about 428.3490343665.

The spelling of 78594721 in words is "seventy-eight million, five hundred ninety-four thousand, seven hundred twenty-one".