78978541 has 2 divisors, whose sum is σ = 78978542. Its totient is φ = 78978540.

The previous prime is 78978509. The next prime is 78978547. The reversal of 78978541 is 14587987.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 78393316 + 585225 = 8854^2 + 765^2 .

It is a cyclic number.

It is not a de Polignac number, because 78978541 - 2⁵ = 78978509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78978547) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39489270 + 39489271.

It is an arithmetic number, because the mean of its divisors is an integer number (39489271).

Almost surely, 2^78978541 is an apocalyptic number.

It is an amenable number.

78978541 is a deficient number, since it is larger than the sum of its proper divisors (1).

78978541 is an equidigital number, since it uses as much as digits as its factorization.

78978541 is an evil number, because the sum of its binary digits is even.

The product of its digits is 564480, while the sum is 49.

The square root of 78978541 is about 8886.9871722649. The cubic root of 78978541 is about 429.0451880684.

The spelling of 78978541 in words is "seventy-eight million, nine hundred seventy-eight thousand, five hundred forty-one".