21700700 has 72 divisors (see below), whose sum is σ = 55725600. Its totient is φ = 7176960.

The previous prime is 21700673. The next prime is 21700703. The reversal of 21700700 is 700712.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21700703) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19766 + ... + 20834.

Almost surely, 2^21700700 is an apocalyptic number.

21700700 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 21700700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27862800).

21700700 is an abundant number, since it is smaller than the sum of its proper divisors (34024900).

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

21700700 is a wasteful number, since it uses less digits than its factorization.

21700700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1119 (or 1112 counting only the distinct ones).

The product of its (nonzero) digits is 98, while the sum is 17.

The square root of 21700700 is about 4658.4010132233. The cubic root of 21700700 is about 278.9274443808.

The spelling of 21700700 in words is "twenty-one million, seven hundred thousand, seven hundred".