78422521 has 4 divisors (see below), whose sum is σ = 78601600. Its totient is φ = 78243444.

The previous prime is 78422503. The next prime is 78422537. The reversal of 78422521 is 12522487.

It is a happy number.

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.

It is a cyclic number.

It is not a de Polignac number, because 78422521 - 2⁵ = 78422489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78422501) 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, 88881 + ... + 89758.

It is an arithmetic number, because the mean of its divisors is an integer number (19650400).

Almost surely, 2^78422521 is an apocalyptic number.

It is an amenable number.

78422521 is a deficient number, since it is larger than the sum of its proper divisors (179079).

78422521 is a wasteful number, since it uses less digits than its factorization.

78422521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179078.

The product of its digits is 8960, while the sum is 31.

The square root of 78422521 is about 8855.6491009976. The cubic root of 78422521 is about 428.0359699149.

The spelling of 78422521 in words is "seventy-eight million, four hundred twenty-two thousand, five hundred twenty-one".