78987481 has 2 divisors, whose sum is σ = 78987482. Its totient is φ = 78987480.

The previous prime is 78987449. The next prime is 78987521. The reversal of 78987481 is 18478987.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 77721856 + 1265625 = 8816^2 + 1125^2 .

It is a cyclic number.

It is not a de Polignac number, because 78987481 - 2⁵ = 78987449 is a prime.

It is a super-2 number, since 2×78987481² = 12478044309450722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78987581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39493740 + 39493741.

It is an arithmetic number, because the mean of its divisors is an integer number (39493741).

Almost surely, 2^78987481 is an apocalyptic number.

It is an amenable number.

78987481 is a deficient number, since it is larger than the sum of its proper divisors (1).

78987481 is an equidigital number, since it uses as much as digits as its factorization.

78987481 is an evil number, because the sum of its binary digits is even.

The product of its digits is 903168, while the sum is 52.

The square root of 78987481 is about 8887.4901406415. The cubic root of 78987481 is about 429.0613760912.

The spelling of 78987481 in words is "seventy-eight million, nine hundred eighty-seven thousand, four hundred eighty-one".