78397757 has 2 divisors, whose sum is σ = 78397758. Its totient is φ = 78397756.

The previous prime is 78397741. The next prime is 78397769. The reversal of 78397757 is 75779387.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 45346756 + 33051001 = 6734^2 + 5749^2 .

It is a cyclic number.

It is not a de Polignac number, because 78397757 - 2⁴ = 78397741 is a prime.

It is a super-2 number, since 2×78397757² = 12292416605262098, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 78397699 and 78397708.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78397057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39198878 + 39198879.

It is an arithmetic number, because the mean of its divisors is an integer number (39198879).

Almost surely, 2^78397757 is an apocalyptic number.

It is an amenable number.

78397757 is a deficient number, since it is larger than the sum of its proper divisors (1).

78397757 is an equidigital number, since it uses as much as digits as its factorization.

78397757 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2593080, while the sum is 53.

The square root of 78397757 is about 8854.2507870514. The cubic root of 78397757 is about 427.9909105852.

The spelling of 78397757 in words is "seventy-eight million, three hundred ninety-seven thousand, seven hundred fifty-seven".