78561937 has 2 divisors, whose sum is σ = 78561938. Its totient is φ = 78561936.

The previous prime is 78561893. The next prime is 78561983. The reversal of 78561937 is 73916587.

It is an a-pointer prime, because the next prime (78561983) can be obtained adding 78561937 to its sum of digits (46).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 52765696 + 25796241 = 7264^2 + 5079^2 .

It is a cyclic number.

It is not a de Polignac number, because 78561937 - 2¹⁹ = 78037649 is a prime.

It is not a weakly prime, because it can be changed into another prime (78561337) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39280968 + 39280969.

It is an arithmetic number, because the mean of its divisors is an integer number (39280969).

Almost surely, 2^78561937 is an apocalyptic number.

It is an amenable number.

78561937 is a deficient number, since it is larger than the sum of its proper divisors (1).

78561937 is an equidigital number, since it uses as much as digits as its factorization.

78561937 is an evil number, because the sum of its binary digits is even.

The product of its digits is 317520, while the sum is 46.

The square root of 78561937 is about 8863.5171912735. The cubic root of 78561937 is about 428.2894673982.

The spelling of 78561937 in words is "seventy-eight million, five hundred sixty-one thousand, nine hundred thirty-seven".