21641700 has 36 divisors (see below), whose sum is σ = 62617520. Its totient is φ = 5771040.

The previous prime is 21641693. The next prime is 21641701. The reversal of 21641700 is 714612.

It is not an unprimeable number, because it can be changed into a prime (21641701) 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, 35770 + ... + 36369.

Almost surely, 2^21641700 is an apocalyptic number.

21641700 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21641700 is an abundant number, since it is smaller than the sum of its proper divisors (40975820).

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

21641700 is a wasteful number, since it uses less digits than its factorization.

21641700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72156 (or 72149 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 21.

The square root of 21641700 is about 4652.0640580284. The cubic root of 21641700 is about 278.6744317131.

The spelling of 21641700 in words is "twenty-one million, six hundred forty-one thousand, seven hundred".