8157220 has 12 divisors (see below), whose sum is σ = 17130204. Its totient is φ = 3262880.

The previous prime is 8157211. The next prime is 8157221. The reversal of 8157220 is 227518.

It can be written as a sum of positive squares in 2 ways, for example, as 2876416 + 5280804 = 1696^2 + 2298^2 .

It is not an unprimeable number, because it can be changed into a prime (8157221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 203911 + ... + 203950.

It is an arithmetic number, because the mean of its divisors is an integer number (1427517).

Almost surely, 2^8157220 is an apocalyptic number.

It is an amenable number.

8157220 is an abundant number, since it is smaller than the sum of its proper divisors (8972984).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

8157220 is a wasteful number, since it uses less digits than its factorization.

8157220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 407870 (or 407868 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 25.

The square root of 8157220 is about 2856.0847326366. The cubic root of 8157220 is about 201.3016764791.

The spelling of 8157220 in words is "eight million, one hundred fifty-seven thousand, two hundred twenty".