1918931415025 has 9 divisors (see below), whose sum is σ = 2379483543243. Its totient is φ = 1535139591000.

The previous prime is 1918931415001. The next prime is 1918931415031. The reversal of 1918931415025 is 5205141398191.

The square root of 1918931415025 is 1385255.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 690815309409 + 1228116105616 = 831153^2 + 1108204^2 .

It is not a de Polignac number, because 1918931415025 - 2²³ = 1918923026417 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1918931415025.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 6787750 + ... + 7064800.

Almost surely, 2^{1918931415025} is an apocalyptic number.

1918931415025 is the 1385255-th square number.

1918931415025 is the 692628-th centered octagonal number.

It is an amenable number.

1918931415025 is a deficient number, since it is larger than the sum of its proper divisors (460552128218).

1918931415025 is an frugal number, since it uses more digits than its factorization.

1918931415025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 554112 (or 277056 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 49.

Multiplying 1918931415025 by its sum of digits (49), we get a square (94027639336225 = 9696785²).

The spelling of 1918931415025 in words is "one trillion, nine hundred eighteen billion, nine hundred thirty-one million, four hundred fifteen thousand, twenty-five".