981491779 has 2 divisors, whose sum is σ = 981491780. Its totient is φ = 981491778.

The previous prime is 981491767. The next prime is 981491783. The reversal of 981491779 is 977194189.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 981491779 - 2¹¹ = 981489731 is a prime.

It is a super-2 number, since 2×981491779² = 1926652224489169682, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (981491729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 490745889 + 490745890.

It is an arithmetic number, because the mean of its divisors is an integer number (490745890).

Almost surely, 2^981491779 is an apocalyptic number.

981491779 is a deficient number, since it is larger than the sum of its proper divisors (1).

981491779 is an equidigital number, since it uses as much as digits as its factorization.

981491779 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1143072, while the sum is 55.

The square root of 981491779 is about 31328.7691906337. The cubic root of 981491779 is about 993.7921351595.

The spelling of 981491779 in words is "nine hundred eighty-one million, four hundred ninety-one thousand, seven hundred seventy-nine".