19949977 has 2 divisors, whose sum is σ = 19949978. Its totient is φ = 19949976.

The previous prime is 19949953. The next prime is 19950013. The reversal of 19949977 is 77994991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16475481 + 3474496 = 4059^2 + 1864^2 .

It is a cyclic number.

It is not a de Polignac number, because 19949977 - 2⁷ = 19949849 is a prime.

It is not a weakly prime, because it can be changed into another prime (19949077) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9974988 + 9974989.

It is an arithmetic number, because the mean of its divisors is an integer number (9974989).

Almost surely, 2^19949977 is an apocalyptic number.

It is an amenable number.

19949977 is a deficient number, since it is larger than the sum of its proper divisors (1).

19949977 is an equidigital number, since it uses as much as digits as its factorization.

19949977 is an odious number, because the sum of its binary digits is odd.

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

The square root of 19949977 is about 4466.5397121262. The cubic root of 19949977 is about 271.2152672015.

It can be divided in two parts, 199 and 49977, that added together give a square (50176 = 224²).

The spelling of 19949977 in words is "nineteen million, nine hundred forty-nine thousand, nine hundred seventy-seven".