1990811641 has 12 divisors (see below), whose sum is σ = 2493984612. Its totient is φ = 1575147168.

The previous prime is 1990811617. The next prime is 1990811651. The reversal of 1990811641 is 1461180991.

It can be written as a sum of positive squares in 2 ways, for example, as 483120400 + 1507691241 = 21980^2 + 38829^2 .

It is not a de Polignac number, because 1990811641 - 2¹³ = 1990803449 is a prime.

It is a super-2 number, since 2×1990811641² = 7926661979882225762, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1990811594 and 1990811603.

It is not an unprimeable number, because it can be changed into a prime (1990811651) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1562010 + ... + 1563283.

It is an arithmetic number, because the mean of its divisors is an integer number (207832051).

Almost surely, 2^1990811641 is an apocalyptic number.

It is an amenable number.

1990811641 is a deficient number, since it is larger than the sum of its proper divisors (503172971).

1990811641 is a wasteful number, since it uses less digits than its factorization.

1990811641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3125320 (or 3125313 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 40.

The square root of 1990811641 is about 44618.5123127161. The cubic root of 1990811641 is about 1257.9886531212.

The spelling of 1990811641 in words is "one billion, nine hundred ninety million, eight hundred eleven thousand, six hundred forty-one".