20861406 has 24 divisors (see below), whose sum is σ = 45288984. Its totient is φ = 6940080.

The previous prime is 20861389. The next prime is 20861413. The reversal of 20861406 is 60416802.

It is a self number, because there is not a number n which added to its sum of digits gives 20861406.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12861 + ... + 14391.

It is an arithmetic number, because the mean of its divisors is an integer number (1887041).

Almost surely, 2^20861406 is an apocalyptic number.

20861406 is an abundant number, since it is smaller than the sum of its proper divisors (24427578).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20861406 is a wasteful number, since it uses less digits than its factorization.

20861406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2296 (or 2293 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 20861406 is about 4567.4288171793. The cubic root of 20861406 is about 275.2841404739.

The spelling of 20861406 in words is "twenty million, eight hundred sixty-one thousand, four hundred six".