78573961 has 2 divisors, whose sum is σ = 78573962. Its totient is φ = 78573960.

The previous prime is 78573959. The next prime is 78573973. The reversal of 78573961 is 16937587.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 74649600 + 3924361 = 8640^2 + 1981^2 .

It is an emirp because it is prime and its reverse (16937587) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78573961 - 2¹ = 78573959 is a prime.

Together with 78573959, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (78573941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39286980 + 39286981.

It is an arithmetic number, because the mean of its divisors is an integer number (39286981).

Almost surely, 2^78573961 is an apocalyptic number.

It is an amenable number.

78573961 is a deficient number, since it is larger than the sum of its proper divisors (1).

78573961 is an equidigital number, since it uses as much as digits as its factorization.

78573961 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 78573961 is about 8864.1954513650. The cubic root of 78573961 is about 428.3113163582.

The spelling of 78573961 in words is "seventy-eight million, five hundred seventy-three thousand, nine hundred sixty-one".