19994977 has 2 divisors, whose sum is σ = 19994978. Its totient is φ = 19994976.

The previous prime is 19994971. The next prime is 19995023. The reversal of 19994977 is 77949991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14814801 + 5180176 = 3849^2 + 2276^2 .

It is a cyclic number.

It is not a de Polignac number, because 19994977 - 2¹⁵ = 19962209 is a prime.

It is not a weakly prime, because it can be changed into another prime (19994971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9997488 + 9997489.

It is an arithmetic number, because the mean of its divisors is an integer number (9997489).

Almost surely, 2^19994977 is an apocalyptic number.

It is an amenable number.

19994977 is a deficient number, since it is larger than the sum of its proper divisors (1).

19994977 is an equidigital number, since it uses as much as digits as its factorization.

19994977 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1285956, while the sum is 55.

The square root of 19994977 is about 4471.5743312619. The cubic root of 19994977 is about 271.4190355574.

The spelling of 19994977 in words is "nineteen million, nine hundred ninety-four thousand, nine hundred seventy-seven".