18775465821 has 24 divisors (see below), whose sum is σ = 31792338240. Its totient is φ = 10727761176.

The previous prime is 18775465799. The next prime is 18775465843. The reversal of 18775465821 is 12856457781.

18775465821 is a `hidden beast` number, since 1 + 8 + 7 + 7 + 54 + 6 + 582 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (18775465799) and next prime (18775465843).

It is not a de Polignac number, because 18775465821 - 2⁵ = 18775465789 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18775465861) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1878780 + ... + 1888746.

It is an arithmetic number, because the mean of its divisors is an integer number (1324680760).

Almost surely, 2^18775465821 is an apocalyptic number.

It is an amenable number.

18775465821 is a deficient number, since it is larger than the sum of its proper divisors (13016872419).

18775465821 is an frugal number, since it uses more digits than its factorization.

18775465821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19950 (or 9977 counting only the distinct ones).

The product of its digits is 3763200, while the sum is 54.

The spelling of 18775465821 in words is "eighteen billion, seven hundred seventy-five million, four hundred sixty-five thousand, eight hundred twenty-one".