20861340 has 48 divisors (see below), whose sum is σ = 59996832. Its totient is φ = 5412096.

The previous prime is 20861339. The next prime is 20861371. The reversal of 20861340 is 4316802.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 20861340.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2479 + ... + 6918.

It is an arithmetic number, because the mean of its divisors is an integer number (1249934).

Almost surely, 2^20861340 is an apocalyptic number.

20861340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20861340 is an abundant number, since it is smaller than the sum of its proper divisors (39135492).

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

20861340 is a wasteful number, since it uses less digits than its factorization.

20861340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9446 (or 9444 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 20861340 is about 4567.4215921020. The cubic root of 20861340 is about 275.2838501647.

The spelling of 20861340 in words is "twenty million, eight hundred sixty-one thousand, three hundred forty".