1868118921 has 6 divisors (see below), whose sum is σ = 2698394010. Its totient is φ = 1245412608.

The previous prime is 1868118887. The next prime is 1868118929. The reversal of 1868118921 is 1298118681.

It can be written as a sum of positive squares in only one way, i.e., 1741893696 + 126225225 = 41736^2 + 11235^2 .

It is not a de Polignac number, because 1868118921 - 2¹³ = 1868110729 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1868118929) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 103784376 + ... + 103784393.

It is an arithmetic number, because the mean of its divisors is an integer number (449732335).

Almost surely, 2^1868118921 is an apocalyptic number.

It is an amenable number.

1868118921 is a deficient number, since it is larger than the sum of its proper divisors (830275089).

1868118921 is a wasteful number, since it uses less digits than its factorization.

1868118921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207568775 (or 207568772 counting only the distinct ones).

The product of its digits is 55296, while the sum is 45.

The square root of 1868118921 is about 43221.7412999523. The cubic root of 1868118921 is about 1231.5957258551.

The spelling of 1868118921 in words is "one billion, eight hundred sixty-eight million, one hundred eighteen thousand, nine hundred twenty-one".