1991887072 has 48 divisors (see below), whose sum is σ = 4577126400. Its totient is φ = 835498368.

The previous prime is 1991887061. The next prime is 1991887087. The reversal of 1991887072 is 2707881991.

It is a super-2 number, since 2×1991887072² = 7935228215201466368, which contains 22 as substring.

It is a congruent number.

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, 84072 + ... + 105127.

It is an arithmetic number, because the mean of its divisors is an integer number (95356800).

Almost surely, 2^1991887072 is an apocalyptic number.

It is an amenable number.

1991887072 is an abundant number, since it is smaller than the sum of its proper divisors (2585239328).

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

1991887072 is a wasteful number, since it uses less digits than its factorization.

1991887072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 189263 (or 189255 counting only the distinct ones).

The product of its (nonzero) digits is 508032, while the sum is 52.

The square root of 1991887072 is about 44630.5620847419. The cubic root of 1991887072 is about 1258.2151330206.

The spelling of 1991887072 in words is "one billion, nine hundred ninety-one million, eight hundred eighty-seven thousand, seventy-two".