20415861 has 32 divisors (see below), whose sum is σ = 33724800. Its totient is φ = 12130560.

The previous prime is 20415859. The next prime is 20415869. The reversal of 20415861 is 16851402.

It is not a de Polignac number, because 20415861 - 2¹ = 20415859 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20415869) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7551 + ... + 9891.

It is an arithmetic number, because the mean of its divisors is an integer number (1053900).

Almost surely, 2^20415861 is an apocalyptic number.

It is an amenable number.

20415861 is a deficient number, since it is larger than the sum of its proper divisors (13308939).

20415861 is a wasteful number, since it uses less digits than its factorization.

20415861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2386 (or 2380 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 20415861 is about 4518.3914173077. The cubic root of 20415861 is about 273.3102378199.

The spelling of 20415861 in words is "twenty million, four hundred fifteen thousand, eight hundred sixty-one".