20077979 has 2 divisors, whose sum is σ = 20077980. Its totient is φ = 20077978.

The previous prime is 20077973. The next prime is 20077997. The reversal of 20077979 is 97977002.

It is a happy number.

Together with next prime (20077997) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20077979 - 2⁴ = 20077963 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (20077973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10038989 + 10038990.

It is an arithmetic number, because the mean of its divisors is an integer number (10038990).

Almost surely, 2^20077979 is an apocalyptic number.

20077979 is a deficient number, since it is larger than the sum of its proper divisors (1).

20077979 is an equidigital number, since it uses as much as digits as its factorization.

20077979 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 55566, while the sum is 41.

The square root of 20077979 is about 4480.8457906962. The cubic root of 20077979 is about 271.7940834460.

The spelling of 20077979 in words is "twenty million, seventy-seven thousand, nine hundred seventy-nine".