21797100 has 252 divisors, whose sum is σ = 79692816. Its totient is φ = 5132160.

The previous prime is 21797093. The next prime is 21797119. The reversal of 21797100 is 179712.

It is a super-2 number, since 2×21797100² = 950227136820000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 83 ways as a sum of consecutive naturals, for example, 947689 + ... + 947711.

Almost surely, 2^21797100 is an apocalyptic number.

21797100 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 21797100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39846408).

21797100 is an abundant number, since it is smaller than the sum of its proper divisors (57895716).

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

21797100 is a wasteful number, since it uses less digits than its factorization.

21797100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68 (or 46 counting only the distinct ones).

The product of its (nonzero) digits is 882, while the sum is 27.

The square root of 21797100 is about 4668.7364457635. The cubic root of 21797100 is about 279.3398563964.

The spelling of 21797100 in words is "twenty-one million, seven hundred ninety-seven thousand, one hundred".