20861460 has 72 divisors (see below), whose sum is σ = 66044160. Its totient is φ = 5320128.

The previous prime is 20861459. The next prime is 20861509. The reversal of 20861460 is 6416802.

20861460 = 241² + 242² + ... + 424².

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1621 + ... + 6659.

It is an arithmetic number, because the mean of its divisors is an integer number (917280).

Almost surely, 2^20861460 is an apocalyptic number.

20861460 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20861460, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33022080).

20861460 is an abundant number, since it is smaller than the sum of its proper divisors (45182700).

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

20861460 is a wasteful number, since it uses less digits than its factorization.

20861460 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5077 (or 5072 counting only the distinct ones).

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

The square root of 20861460 is about 4567.4347285977. The cubic root of 20861460 is about 275.2843779991.

It can be divided in two parts, 20861 and 460, that added together give a triangular number (21321 = T₂₀₆).

The spelling of 20861460 in words is "twenty million, eight hundred sixty-one thousand, four hundred sixty".