84978791 has 2 divisors, whose sum is σ = 84978792. Its totient is φ = 84978790.

The previous prime is 84978779. The next prime is 84978797. The reversal of 84978791 is 19787948.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 84978791 - 2⁶ = 84978727 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84978797) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42489395 + 42489396.

It is an arithmetic number, because the mean of its divisors is an integer number (42489396).

Almost surely, 2^84978791 is an apocalyptic number.

84978791 is a deficient number, since it is larger than the sum of its proper divisors (1).

84978791 is an equidigital number, since it uses as much as digits as its factorization.

84978791 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1016064, while the sum is 53.

The square root of 84978791 is about 9218.3941660139. The cubic root of 84978791 is about 439.6463946207.

The spelling of 84978791 in words is "eighty-four million, nine hundred seventy-eight thousand, seven hundred ninety-one".