840061979 has 2 divisors, whose sum is σ = 840061980. Its totient is φ = 840061978.

The previous prime is 840061969. The next prime is 840061993. The reversal of 840061979 is 979160048.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 840061979 - 2⁸ = 840061723 is a prime.

It is a super-2 number, since 2×840061979² = 1411408257122792882, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (840061969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 420030989 + 420030990.

It is an arithmetic number, because the mean of its divisors is an integer number (420030990).

Almost surely, 2^840061979 is an apocalyptic number.

840061979 is a deficient number, since it is larger than the sum of its proper divisors (1).

840061979 is an equidigital number, since it uses as much as digits as its factorization.

840061979 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108864, while the sum is 44.

The square root of 840061979 is about 28983.8227119888. The cubic root of 840061979 is about 943.5620016795.

The spelling of 840061979 in words is "eight hundred forty million, sixty-one thousand, nine hundred seventy-nine".