20315891 has 8 divisors (see below), whose sum is σ = 20829504. Its totient is φ = 19805760.

The previous prime is 20315887. The next prime is 20315917. The reversal of 20315891 is 19851302.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20315891 - 2² = 20315887 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20315821) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14021 + ... + 15401.

It is an arithmetic number, because the mean of its divisors is an integer number (2603688).

Almost surely, 2^20315891 is an apocalyptic number.

20315891 is a deficient number, since it is larger than the sum of its proper divisors (513613).

20315891 is a wasteful number, since it uses less digits than its factorization.

20315891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1741.

The product of its (nonzero) digits is 2160, while the sum is 29.

The square root of 20315891 is about 4507.3152763036. The cubic root of 20315891 is about 272.8634031544.

The spelling of 20315891 in words is "twenty million, three hundred fifteen thousand, eight hundred ninety-one".