21351150 has 72 divisors (see below), whose sum is σ = 60759504. Its totient is φ = 5356800.

The previous prime is 21351131. The next prime is 21351181. The reversal of 21351150 is 5115312.

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

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 6255 + ... + 9045.

It is an arithmetic number, because the mean of its divisors is an integer number (843882).

Almost surely, 2^21351150 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21351150, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30379752).

21351150 is an abundant number, since it is smaller than the sum of its proper divisors (39408354).

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

21351150 is a wasteful number, since it uses less digits than its factorization.

21351150 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2826 (or 2818 counting only the distinct ones).

The product of its (nonzero) digits is 150, while the sum is 18.

The square root of 21351150 is about 4620.7304617344. The cubic root of 21351150 is about 277.4216969234.

Adding to 21351150 its reverse (5115312), we get a palindrome (26466462).

The spelling of 21351150 in words is "twenty-one million, three hundred fifty-one thousand, one hundred fifty".