20401919 has 2 divisors, whose sum is σ = 20401920. Its totient is φ = 20401918.

The previous prime is 20401867. The next prime is 20401933. The reversal of 20401919 is 91910402.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20401919 - 2⁸ = 20401663 is a prime.

It is a super-2 number, since 2×20401919² = 832476597765122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20401219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10200959 + 10200960.

It is an arithmetic number, because the mean of its divisors is an integer number (10200960).

Almost surely, 2^20401919 is an apocalyptic number.

20401919 is a deficient number, since it is larger than the sum of its proper divisors (1).

20401919 is an equidigital number, since it uses as much as digits as its factorization.

20401919 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 26.

The square root of 20401919 is about 4516.8483481295. The cubic root of 20401919 is about 273.2480090939.

The spelling of 20401919 in words is "twenty million, four hundred one thousand, nine hundred nineteen".