1869859921 has 2 divisors, whose sum is σ = 1869859922. Its totient is φ = 1869859920.

The previous prime is 1869859909. The next prime is 1869859933. The reversal of 1869859921 is 1299589681.

It is a balanced prime because it is at equal distance from previous prime (1869859909) and next prime (1869859933).

It can be written as a sum of positive squares in only one way, i.e., 1386519696 + 483340225 = 37236^2 + 21985^2 .

It is a cyclic number.

It is not a de Polignac number, because 1869859921 - 2⁵ = 1869859889 is a prime.

It is a super-2 number, since 2×1869859921² = 6992752248324252482, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1869859951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 934929960 + 934929961.

It is an arithmetic number, because the mean of its divisors is an integer number (934929961).

Almost surely, 2^1869859921 is an apocalyptic number.

It is an amenable number.

1869859921 is a deficient number, since it is larger than the sum of its proper divisors (1).

1869859921 is an equidigital number, since it uses as much as digits as its factorization.

1869859921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2799360, while the sum is 58.

The square root of 1869859921 is about 43241.8769365993. The cubic root of 1869859921 is about 1231.9782037189.

The spelling of 1869859921 in words is "one billion, eight hundred sixty-nine million, eight hundred fifty-nine thousand, nine hundred twenty-one".