78552121 has 8 divisors (see below), whose sum is σ = 83318760. Its totient is φ = 73801728.

The previous prime is 78552119. The next prime is 78552127. The reversal of 78552121 is 12125587.

It can be written as a sum of positive squares in 4 ways, for example, as 4247721 + 74304400 = 2061^2 + 8620^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 78552121 - 2¹ = 78552119 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78552127) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6745 + ... + 14233.

It is an arithmetic number, because the mean of its divisors is an integer number (10414845).

Almost surely, 2^78552121 is an apocalyptic number.

It is an amenable number.

78552121 is a deficient number, since it is larger than the sum of its proper divisors (4766639).

78552121 is a wasteful number, since it uses less digits than its factorization.

78552121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8123.

The product of its digits is 5600, while the sum is 31.

The square root of 78552121 is about 8862.9634434539. The cubic root of 78552121 is about 428.2716289696.

The spelling of 78552121 in words is "seventy-eight million, five hundred fifty-two thousand, one hundred twenty-one".