20119991 has 2 divisors, whose sum is σ = 20119992. Its totient is φ = 20119990.

The previous prime is 20119987. The next prime is 20120029. The reversal of 20119991 is 19991102.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20119991 - 2² = 20119987 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20119091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10059995 + 10059996.

It is an arithmetic number, because the mean of its divisors is an integer number (10059996).

Almost surely, 2^20119991 is an apocalyptic number.

20119991 is a deficient number, since it is larger than the sum of its proper divisors (1).

20119991 is an equidigital number, since it uses as much as digits as its factorization.

20119991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1458, while the sum is 32.

The square root of 20119991 is about 4485.5312951756. The cubic root of 20119991 is about 271.9835224664.

The spelling of 20119991 in words is "twenty million, one hundred nineteen thousand, nine hundred ninety-one".