78324553 has 2 divisors, whose sum is σ = 78324554. Its totient is φ = 78324552.

The previous prime is 78324551. The next prime is 78324613. The reversal of 78324553 is 35542387.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 77492809 + 831744 = 8803^2 + 912^2 .

It is a cyclic number.

It is not a de Polignac number, because 78324553 - 2¹ = 78324551 is a prime.

It is a super-2 number, since 2×78324553² = 12269471205299618, which contains 22 as substring.

Together with 78324551, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (78324551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39162276 + 39162277.

It is an arithmetic number, because the mean of its divisors is an integer number (39162277).

Almost surely, 2^78324553 is an apocalyptic number.

It is an amenable number.

78324553 is a deficient number, since it is larger than the sum of its proper divisors (1).

78324553 is an equidigital number, since it uses as much as digits as its factorization.

78324553 is an evil number, because the sum of its binary digits is even.

The product of its digits is 100800, while the sum is 37.

The square root of 78324553 is about 8850.1159879405. The cubic root of 78324553 is about 427.8576567586.

The spelling of 78324553 in words is "seventy-eight million, three hundred twenty-four thousand, five hundred fifty-three".