78144553 has 2 divisors, whose sum is σ = 78144554. Its totient is φ = 78144552.

The previous prime is 78144551. The next prime is 78144557. The reversal of 78144553 is 35544187.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 78092569 + 51984 = 8837^2 + 228^2 .

It is a cyclic number.

It is not a de Polignac number, because 78144553 - 2¹ = 78144551 is a prime.

It is a super-2 number, since 2×78144553² = 12213142327139618, which contains 22 as substring.

Together with 78144551, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (78144551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39072276 + 39072277.

It is an arithmetic number, because the mean of its divisors is an integer number (39072277).

Almost surely, 2^78144553 is an apocalyptic number.

It is an amenable number.

78144553 is a deficient number, since it is larger than the sum of its proper divisors (1).

78144553 is an equidigital number, since it uses as much as digits as its factorization.

78144553 is an evil number, because the sum of its binary digits is even.

The product of its digits is 67200, while the sum is 37.

The square root of 78144553 is about 8839.9407803446. The cubic root of 78144553 is about 427.5296478646.

The spelling of 78144553 in words is "seventy-eight million, one hundred forty-four thousand, five hundred fifty-three".