1971911856 has 40 divisors (see below), whose sum is σ = 5097463920. Its totient is φ = 656870656.

The previous prime is 1971911819. The next prime is 1971911863. The reversal of 1971911856 is 6581191791.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 64690 + ... + 90158.

It is an arithmetic number, because the mean of its divisors is an integer number (127436598).

Almost surely, 2^1971911856 is an apocalyptic number.

1971911856 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1971911856 is an abundant number, since it is smaller than the sum of its proper divisors (3125552064).

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

1971911856 is a wasteful number, since it uses less digits than its factorization.

1971911856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27093 (or 27087 counting only the distinct ones).

The product of its digits is 136080, while the sum is 48.

The square root of 1971911856 is about 44406.2141597322. The cubic root of 1971911856 is about 1253.9950804759.

The spelling of 1971911856 in words is "one billion, nine hundred seventy-one million, nine hundred eleven thousand, eight hundred fifty-six".