20661420 has 48 divisors (see below), whose sum is σ = 62304480. Its totient is φ = 5085696.

The previous prime is 20661419. The next prime is 20661437. The reversal of 20661420 is 2416602.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12465 + ... + 14024.

It is an arithmetic number, because the mean of its divisors is an integer number (1298010).

Almost surely, 2^20661420 is an apocalyptic number.

20661420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20661420 is an abundant number, since it is smaller than the sum of its proper divisors (41643060).

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

20661420 is a wasteful number, since it uses less digits than its factorization.

20661420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26514 (or 26512 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 20661420 is about 4545.4834726352. The cubic root of 20661420 is about 274.4016522211.

It can be divided in two parts, 2066 and 1420, that added together give a triangular number (3486 = T₈₃).

The spelling of 20661420 in words is "twenty million, six hundred sixty-one thousand, four hundred twenty".