21907000 has 64 divisors (see below), whose sum is σ = 54007200. Its totient is φ = 8294400.

The previous prime is 21906961. The next prime is 21907007. The reversal of 21907000 is 70912.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21907007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18424 + ... + 19576.

Almost surely, 2^21907000 is an apocalyptic number.

21907000 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 21907000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27003600).

21907000 is an abundant number, since it is smaller than the sum of its proper divisors (32100200).

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

21907000 is a wasteful number, since it uses less digits than its factorization.

21907000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1193 (or 1179 counting only the distinct ones).

The product of its (nonzero) digits is 126, while the sum is 19.

The square root of 21907000 is about 4680.4914271901. The cubic root of 21907000 is about 279.8085425851.

Adding to 21907000 its reverse (70912), we get a palindrome (21977912).

The spelling of 21907000 in words is "twenty-one million, nine hundred seven thousand".