78458557 has 4 divisors (see below), whose sum is σ = 80127936. Its totient is φ = 76789180.

The previous prime is 78458533. The next prime is 78458579. The reversal of 78458557 is 75585487.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 75585487 = 37 ⋅2042851.

It is a cyclic number.

It is not a de Polignac number, because 78458557 - 2¹¹ = 78456509 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 78458557.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78458507) 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, 834619 + ... + 834712.

It is an arithmetic number, because the mean of its divisors is an integer number (20031984).

Almost surely, 2^78458557 is an apocalyptic number.

It is an amenable number.

78458557 is a deficient number, since it is larger than the sum of its proper divisors (1669379).

78458557 is a wasteful number, since it uses less digits than its factorization.

78458557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1669378.

The product of its digits is 1568000, while the sum is 49.

The square root of 78458557 is about 8857.6835007806. The cubic root of 78458557 is about 428.1015222673.

The spelling of 78458557 in words is "seventy-eight million, four hundred fifty-eight thousand, five hundred fifty-seven".