80778637 has 2 divisors, whose sum is σ = 80778638. Its totient is φ = 80778636.

The previous prime is 80778629. The next prime is 80778647. The reversal of 80778637 is 73687708.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 61011721 + 19766916 = 7811^2 + 4446^2 .

It is a cyclic number.

It is not a de Polignac number, because 80778637 - 2³ = 80778629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (80778647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40389318 + 40389319.

It is an arithmetic number, because the mean of its divisors is an integer number (40389319).

Almost surely, 2^80778637 is an apocalyptic number.

It is an amenable number.

80778637 is a deficient number, since it is larger than the sum of its proper divisors (1).

80778637 is an equidigital number, since it uses as much as digits as its factorization.

80778637 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 395136, while the sum is 46.

The square root of 80778637 is about 8987.6936418639. The cubic root of 80778637 is about 432.2803624906.

The spelling of 80778637 in words is "eighty million, seven hundred seventy-eight thousand, six hundred thirty-seven".