1872266921 has 12 divisors (see below), whose sum is σ = 2189009988. Its totient is φ = 1596645792.

The previous prime is 1872266887. The next prime is 1872266959. The reversal of 1872266921 is 1296622781.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1058591296 + 813675625 = 32536^2 + 28525^2 .

It is not a de Polignac number, because 1872266921 - 2⁶ = 1872266857 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1872260921) 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, 87326 + ... + 106631.

It is an arithmetic number, because the mean of its divisors is an integer number (182417499).

Almost surely, 2^1872266921 is an apocalyptic number.

It is an amenable number.

1872266921 is a deficient number, since it is larger than the sum of its proper divisors (316743067).

1872266921 is a wasteful number, since it uses less digits than its factorization.

1872266921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 194168 (or 194161 counting only the distinct ones).

The product of its digits is 145152, while the sum is 44.

The square root of 1872266921 is about 43269.6998025177. The cubic root of 1872266921 is about 1232.5066033793.

The spelling of 1872266921 in words is "one billion, eight hundred seventy-two million, two hundred sixty-six thousand, nine hundred twenty-one".