84078581 has 2 divisors, whose sum is σ = 84078582. Its totient is φ = 84078580.

The previous prime is 84078571. The next prime is 84078587. The reversal of 84078581 is 18587048.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 82719025 + 1359556 = 9095^2 + 1166^2 .

It is a cyclic number.

It is not a de Polignac number, because 84078581 - 2⁶ = 84078517 is a prime.

It is a super-2 number, since 2×84078581² = 14138415565947122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84078587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42039290 + 42039291.

It is an arithmetic number, because the mean of its divisors is an integer number (42039291).

Almost surely, 2^84078581 is an apocalyptic number.

It is an amenable number.

84078581 is a deficient number, since it is larger than the sum of its proper divisors (1).

84078581 is an equidigital number, since it uses as much as digits as its factorization.

84078581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 71680, while the sum is 41.

The square root of 84078581 is about 9169.4373327920. The cubic root of 84078581 is about 438.0884376928.

The spelling of 84078581 in words is "eighty-four million, seventy-eight thousand, five hundred eighty-one".