78257797 has 4 divisors (see below), whose sum is σ = 78294220. Its totient is φ = 78221376.

The previous prime is 78257771. The next prime is 78257801. The reversal of 78257797 is 79775287.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15752961 + 62504836 = 3969^2 + 7906^2 .

It is a cyclic number.

It is not a de Polignac number, because 78257797 - 2¹⁵ = 78225029 is a prime.

It is a super-2 number, since 2×78257797² = 12248565582586418, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78257717) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14772 + ... + 19357.

It is an arithmetic number, because the mean of its divisors is an integer number (19573555).

Almost surely, 2^78257797 is an apocalyptic number.

It is an amenable number.

78257797 is a deficient number, since it is larger than the sum of its proper divisors (36423).

78257797 is a wasteful number, since it uses less digits than its factorization.

78257797 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36422.

The product of its digits is 1728720, while the sum is 52.

The square root of 78257797 is about 8846.3437079960. The cubic root of 78257797 is about 427.7360678784.

The spelling of 78257797 in words is "seventy-eight million, two hundred fifty-seven thousand, seven hundred ninety-seven".