981145990 has 128 divisors (see below), whose sum is σ = 2131992576. Its totient is φ = 321024000.

The previous prime is 981145981. The next prime is 981145999. The reversal of 981145990 is 99541189.

It is an interprime number because it is at equal distance from previous prime (981145981) and next prime (981145999).

It is a Smith number, since the sum of its digits (46) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 981145990.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (981145999) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 5136795 + ... + 5136985.

It is an arithmetic number, because the mean of its divisors is an integer number (16656192).

Almost surely, 2^981145990 is an apocalyptic number.

981145990 is the 15662-nd decagonal number.

981145990 is an abundant number, since it is smaller than the sum of its proper divisors (1150846586).

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

981145990 is a wasteful number, since it uses less digits than its factorization.

981145990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 334.

The product of its (nonzero) digits is 116640, while the sum is 46.

The square root of 981145990 is about 31323.2499910210. The cubic root of 981145990 is about 993.6754139398.

The spelling of 981145990 in words is "nine hundred eighty-one million, one hundred forty-five thousand, nine hundred ninety".