1991994472 has 16 divisors (see below), whose sum is σ = 4022296740. Its totient is φ = 919382016.

The previous prime is 1991994463. The next prime is 1991994481. The reversal of 1991994472 is 2744991991.

It is an interprime number because it is at equal distance from previous prime (1991994463) and next prime (1991994481).

It can be written as a sum of positive squares in 2 ways, for example, as 1446585156 + 545409316 = 38034^2 + 23354^2 .

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, 9576793 + ... + 9577000.

Almost surely, 2^1991994472 is an apocalyptic number.

It is an amenable number.

1991994472 is an abundant number, since it is smaller than the sum of its proper divisors (2030302268).

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

1991994472 is a wasteful number, since it uses less digits than its factorization.

1991994472 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19153812 (or 19153808 counting only the distinct ones).

The product of its digits is 1469664, while the sum is 55.

The square root of 1991994472 is about 44631.7652798990. The cubic root of 1991994472 is about 1258.2377463971.

The spelling of 1991994472 in words is "one billion, nine hundred ninety-one million, nine hundred ninety-four thousand, four hundred seventy-two".