1945398990 has 32 divisors (see below), whose sum is σ = 4670176896. Its totient is φ = 518637600.

The previous prime is 1945398989. The next prime is 1945398997. The reversal of 1945398990 is 998935491.

It is a self number, because there is not a number n which added to its sum of digits gives 1945398990.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1945398997) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 169989 + ... + 181071.

It is an arithmetic number, because the mean of its divisors is an integer number (145943028).

Almost surely, 2^1945398990 is an apocalyptic number.

1945398990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1945398990 is an abundant number, since it is smaller than the sum of its proper divisors (2724777906).

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

1945398990 is a wasteful number, since it uses less digits than its factorization.

1945398990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16944.

The product of its (nonzero) digits is 3149280, while the sum is 57.

The square root of 1945398990 is about 44106.6773856295. The cubic root of 1945398990 is about 1248.3496064533.

The spelling of 1945398990 in words is "one billion, nine hundred forty-five million, three hundred ninety-eight thousand, nine hundred ninety".