78399953 has 2 divisors, whose sum is σ = 78399954. Its totient is φ = 78399952.

The previous prime is 78399941. The next prime is 78399973. The reversal of 78399953 is 35999387.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 77035729 + 1364224 = 8777^2 + 1168^2 .

It is a cyclic number.

It is not a de Polignac number, because 78399953 - 2⁶ = 78399889 is a prime.

It is a super-2 number, since 2×78399953² = 12293105260804418, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 78399895 and 78399904.

It is not a weakly prime, because it can be changed into another prime (78399973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39199976 + 39199977.

It is an arithmetic number, because the mean of its divisors is an integer number (39199977).

Almost surely, 2^78399953 is an apocalyptic number.

It is an amenable number.

78399953 is a deficient number, since it is larger than the sum of its proper divisors (1).

78399953 is an equidigital number, since it uses as much as digits as its factorization.

78399953 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1837080, while the sum is 53.

The square root of 78399953 is about 8854.3747944166. The cubic root of 78399953 is about 427.9949066998.

The spelling of 78399953 in words is "seventy-eight million, three hundred ninety-nine thousand, nine hundred fifty-three".