1971861356 has 12 divisors (see below), whose sum is σ = 3507327600. Its totient is φ = 969767760.

The previous prime is 1971861319. The next prime is 1971861371. The reversal of 1971861356 is 6531681791.

It is a hoax number, since the sum of its digits (47) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 1971861356.

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, 4040456 + ... + 4040943.

It is an arithmetic number, because the mean of its divisors is an integer number (292277300).

Almost surely, 2^1971861356 is an apocalyptic number.

It is an amenable number.

1971861356 is a deficient number, since it is larger than the sum of its proper divisors (1535466244).

1971861356 is a wasteful number, since it uses less digits than its factorization.

1971861356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8081464 (or 8081462 counting only the distinct ones).

The product of its digits is 272160, while the sum is 47.

The square root of 1971861356 is about 44405.6455419804. The cubic root of 1971861356 is about 1253.9843755870.

The spelling of 1971861356 in words is "one billion, nine hundred seventy-one million, eight hundred sixty-one thousand, three hundred fifty-six".