20977799 has 2 divisors, whose sum is σ = 20977800. Its totient is φ = 20977798.

The previous prime is 20977783. The next prime is 20977811. The reversal of 20977799 is 99777902.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20977799 - 2⁴ = 20977783 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20977709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10488899 + 10488900.

It is an arithmetic number, because the mean of its divisors is an integer number (10488900).

Almost surely, 2^20977799 is an apocalyptic number.

20977799 is a deficient number, since it is larger than the sum of its proper divisors (1).

20977799 is an equidigital number, since it uses as much as digits as its factorization.

20977799 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 500094, while the sum is 50.

The square root of 20977799 is about 4580.1527267112. The cubic root of 20977799 is about 275.7951597446.

The spelling of 20977799 in words is "twenty million, nine hundred seventy-seven thousand, seven hundred ninety-nine".