18057821961 has 32 divisors (see below), whose sum is σ = 24833450880. Its totient is φ = 11667142656.

The previous prime is 18057821941. The next prime is 18057822001. The reversal of 18057821961 is 16912875081.

It is a happy number.

It is not a de Polignac number, because 18057821961 - 2¹⁵ = 18057789193 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18057821961.

It is not an unprimeable number, because it can be changed into a prime (18057821941) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4753915 + ... + 4757711.

It is an arithmetic number, because the mean of its divisors is an integer number (776045340).

Almost surely, 2^18057821961 is an apocalyptic number.

It is an amenable number.

18057821961 is a deficient number, since it is larger than the sum of its proper divisors (6775628919).

18057821961 is a wasteful number, since it uses less digits than its factorization.

18057821961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4233.

The product of its (nonzero) digits is 241920, while the sum is 48.

The spelling of 18057821961 in words is "eighteen billion, fifty-seven million, eight hundred twenty-one thousand, nine hundred sixty-one".