78402901 has 2 divisors, whose sum is σ = 78402902. Its totient is φ = 78402900.

The previous prime is 78402893. The next prime is 78402941. The reversal of 78402901 is 10920487.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 56640676 + 21762225 = 7526^2 + 4665^2 .

It is a cyclic number.

It is not a de Polignac number, because 78402901 - 2³ = 78402893 is a prime.

It is a super-2 number, since 2×78402901² = 12294029770431602, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78402941) 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, 39201450 + 39201451.

It is an arithmetic number, because the mean of its divisors is an integer number (39201451).

Almost surely, 2^78402901 is an apocalyptic number.

It is an amenable number.

78402901 is a deficient number, since it is larger than the sum of its proper divisors (1).

78402901 is an equidigital number, since it uses as much as digits as its factorization.

78402901 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 78402901 is about 8854.5412642327. The cubic root of 78402901 is about 428.0002711298. Note that the first 3 decimals are identical.

The spelling of 78402901 in words is "seventy-eight million, four hundred two thousand, nine hundred one".