20661700 has 36 divisors (see below), whose sum is σ = 45278352. Its totient is φ = 8183200.

The previous prime is 20661691. The next prime is 20661703. The reversal of 20661700 is 716602.

It is not an unprimeable number, because it can be changed into a prime (20661703) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9735 + ... + 11665.

It is an arithmetic number, because the mean of its divisors is an integer number (1257732).

Almost surely, 2^20661700 is an apocalyptic number.

20661700 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 20661700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22639176).

20661700 is an abundant number, since it is smaller than the sum of its proper divisors (24616652).

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

20661700 is a wasteful number, since it uses less digits than its factorization.

20661700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2052 (or 2045 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 22.

The square root of 20661700 is about 4545.5142723349. The cubic root of 20661700 is about 274.4028917635.

The spelling of 20661700 in words is "twenty million, six hundred sixty-one thousand, seven hundred".