823156240 has 20 divisors (see below), whose sum is σ = 1913838444. Its totient is φ = 329262464.

The previous prime is 823156207. The next prime is 823156277. The reversal of 823156240 is 42651328.

It can be written as a sum of positive squares in 2 ways, for example, as 601622784 + 221533456 = 24528^2 + 14884^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5144647 + ... + 5144806.

Almost surely, 2^823156240 is an apocalyptic number.

823156240 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

823156240 is an abundant number, since it is smaller than the sum of its proper divisors (1090682204).

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

823156240 is a wasteful number, since it uses less digits than its factorization.

823156240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10289466 (or 10289460 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 31.

The square root of 823156240 is about 28690.6995383521. The cubic root of 823156240 is about 937.1895230260.

The spelling of 823156240 in words is "eight hundred twenty-three million, one hundred fifty-six thousand, two hundred forty".