20053991 has 2 divisors, whose sum is σ = 20053992. Its totient is φ = 20053990.

The previous prime is 20053951. The next prime is 20054003. The reversal of 20053991 is 19935002.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20053991 - 2⁶ = 20053927 is a prime.

It is equal to p_1273835 and since 20053991 and 1273835 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20053951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10026995 + 10026996.

It is an arithmetic number, because the mean of its divisors is an integer number (10026996).

Almost surely, 2^20053991 is an apocalyptic number.

20053991 is a deficient number, since it is larger than the sum of its proper divisors (1).

20053991 is an equidigital number, since it uses as much as digits as its factorization.

20053991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2430, while the sum is 29.

The square root of 20053991 is about 4478.1682639222. The cubic root of 20053991 is about 271.6857990632.

Adding to 20053991 its reverse (19935002), we get a palindrome (39988993).

The spelling of 20053991 in words is "twenty million, fifty-three thousand, nine hundred ninety-one".