20515841 has 4 divisors (see below), whose sum is σ = 20594112. Its totient is φ = 20437572.

The previous prime is 20515837. The next prime is 20515853. The reversal of 20515841 is 14851502.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20515841 - 2² = 20515837 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20515841.

It is not an unprimeable number, because it can be changed into a prime (20515811) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38741 + ... + 39266.

It is an arithmetic number, because the mean of its divisors is an integer number (5148528).

Almost surely, 2^20515841 is an apocalyptic number.

It is an amenable number.

20515841 is a deficient number, since it is larger than the sum of its proper divisors (78271).

20515841 is an equidigital number, since it uses as much as digits as its factorization.

20515841 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78270.

The product of its (nonzero) digits is 1600, while the sum is 26.

The square root of 20515841 is about 4529.4415770600. The cubic root of 20515841 is about 273.7556606629.

The spelling of 20515841 in words is "twenty million, five hundred fifteen thousand, eight hundred forty-one".