981901919 has 4 divisors (see below), whose sum is σ = 981995496. Its totient is φ = 981808344.

The previous prime is 981901909. The next prime is 981901939. The reversal of 981901919 is 919109189.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-981901919 is a prime.

It is a super-2 number, since 2×981901919² = 1928262757071765122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (981901909) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28724 + ... + 52809.

It is an arithmetic number, because the mean of its divisors is an integer number (245498874).

Almost surely, 2^981901919 is an apocalyptic number.

981901919 is a deficient number, since it is larger than the sum of its proper divisors (93577).

981901919 is a wasteful number, since it uses less digits than its factorization.

981901919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93576.

The product of its (nonzero) digits is 52488, while the sum is 47.

The square root of 981901919 is about 31335.3142476663. The cubic root of 981901919 is about 993.9305425491.

The spelling of 981901919 in words is "nine hundred eighty-one million, nine hundred one thousand, nine hundred nineteen".