3157811820 has 144 divisors (see below), whose sum is σ = 9751891968. Its totient is φ = 827003520.

The previous prime is 3157811819. The next prime is 3157811849. The reversal of 3157811820 is 281187513.

3157811820 is a `hidden beast` number, since 3 + 1 + 578 + 1 + 1 + 82 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2445375 + ... + 2446665.

It is an arithmetic number, because the mean of its divisors is an integer number (67721472).

Almost surely, 2^3157811820 is an apocalyptic number.

3157811820 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 3157811820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4875945984).

3157811820 is an abundant number, since it is smaller than the sum of its proper divisors (6594080148).

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

3157811820 is a wasteful number, since it uses less digits than its factorization.

3157811820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1540 (or 1535 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 36.

The square root of 3157811820 is about 56194.4109320491. The cubic root of 3157811820 is about 1467.1079889781.

The spelling of 3157811820 in words is "three billion, one hundred fifty-seven million, eight hundred eleven thousand, eight hundred twenty".