21712700 has 36 divisors (see below), whose sum is σ = 47418840. Its totient is φ = 8629440.

The previous prime is 21712697. The next prime is 21712729. The reversal of 21712700 is 721712.

It is a Harshad number since it is a multiple of its sum of digits (20).

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, 17294 + ... + 18506.

It is an arithmetic number, because the mean of its divisors is an integer number (1317190).

Almost surely, 2^21712700 is an apocalyptic number.

21712700 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 21712700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23709420).

21712700 is an abundant number, since it is smaller than the sum of its proper divisors (25706140).

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

21712700 is a wasteful number, since it uses less digits than its factorization.

21712700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1406 (or 1399 counting only the distinct ones).

The product of its (nonzero) digits is 196, while the sum is 20.

The square root of 21712700 is about 4659.6888308126. The cubic root of 21712700 is about 278.9788484455.

The spelling of 21712700 in words is "twenty-one million, seven hundred twelve thousand, seven hundred".