21900060 has 216 divisors, whose sum is σ = 83655936. Its totient is φ = 4596480.

The previous prime is 21900059. The next prime is 21900091. The reversal of 21900060 is 6000912.

It is a super-2 number, since 2×21900060² = 959225256007200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 114565 + ... + 114755.

It is an arithmetic number, because the mean of its divisors is an integer number (387296).

Almost surely, 2^21900060 is an apocalyptic number.

21900060 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 21900060, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41827968).

21900060 is an abundant number, since it is smaller than the sum of its proper divisors (61755876).

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

21900060 is a wasteful number, since it uses less digits than its factorization.

21900060 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 233 (or 221 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

The square root of 21900060 is about 4679.7499933223. The cubic root of 21900060 is about 279.7789922682.

Adding to 21900060 its reverse (6000912), we get a palindrome (27900972).

The spelling of 21900060 in words is "twenty-one million, nine hundred thousand, sixty".