1945021788 has 24 divisors (see below), whose sum is σ = 5042649360. Its totient is φ = 648340560.

The previous prime is 1945021781. The next prime is 1945021807. The reversal of 1945021788 is 8871205491.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1945021781) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9004623 + ... + 9004838.

It is an arithmetic number, because the mean of its divisors is an integer number (210110390).

Almost surely, 2^1945021788 is an apocalyptic number.

1945021788 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1945021788 is an abundant number, since it is smaller than the sum of its proper divisors (3097627572).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1945021788 is a wasteful number, since it uses less digits than its factorization.

1945021788 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18009474 (or 18009466 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 45.

The square root of 1945021788 is about 44102.4011591206. The cubic root of 1945021788 is about 1248.2689185656.

The spelling of 1945021788 in words is "one billion, nine hundred forty-five million, twenty-one thousand, seven hundred eighty-eight".