20995191 has 24 divisors (see below), whose sum is σ = 34904064. Its totient is φ = 11912400.

The previous prime is 20995147. The next prime is 20995193. The reversal of 20995191 is 19159902.

It is not a de Polignac number, because 20995191 - 2⁶ = 20995127 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20995193) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8410 + ... + 10616.

It is an arithmetic number, because the mean of its divisors is an integer number (1454336).

Almost surely, 2^20995191 is an apocalyptic number.

20995191 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

20995191 is a deficient number, since it is larger than the sum of its proper divisors (13908873).

20995191 is a wasteful number, since it uses less digits than its factorization.

20995191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2371 (or 2368 counting only the distinct ones).

The product of its (nonzero) digits is 7290, while the sum is 36.

The square root of 20995191 is about 4582.0509599960. The cubic root of 20995191 is about 275.8713562425.

The spelling of 20995191 in words is "twenty million, nine hundred ninety-five thousand, one hundred ninety-one".