1899768645 has 12 divisors (see below), whose sum is σ = 3292932396. Its totient is φ = 1013209920.

The previous prime is 1899768643. The next prime is 1899768659. The reversal of 1899768645 is 5468679981.

It can be written as a sum of positive squares in 2 ways, for example, as 798458049 + 1101310596 = 28257^2 + 33186^2 .

It is not a de Polignac number, because 1899768645 - 2¹ = 1899768643 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1899768643) 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, 21108496 + ... + 21108585.

It is an arithmetic number, because the mean of its divisors is an integer number (274411033).

Almost surely, 2^1899768645 is an apocalyptic number.

1899768645 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1899768645 is a deficient number, since it is larger than the sum of its proper divisors (1393163751).

1899768645 is a wasteful number, since it uses less digits than its factorization.

1899768645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42217092 (or 42217089 counting only the distinct ones).

The product of its digits is 26127360, while the sum is 63.

The square root of 1899768645 is about 43586.3355307601. The cubic root of 1899768645 is about 1238.5120560830.

The spelling of 1899768645 in words is "one billion, eight hundred ninety-nine million, seven hundred sixty-eight thousand, six hundred forty-five".