21901032 has 96 divisors (see below), whose sum is σ = 65075400. Its totient is φ = 6623232.

The previous prime is 21901021. The next prime is 21901051. The reversal of 21901032 is 23010912.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 16112196 + 5788836 = 4014^2 + 2406^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 21900996 and 21901014.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 35188 + ... + 35804.

Almost surely, 2^21901032 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21901032, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32537700).

21901032 is an abundant number, since it is smaller than the sum of its proper divisors (43174368).

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

21901032 is a wasteful number, since it uses less digits than its factorization.

21901032 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 675 (or 668 counting only the distinct ones).

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

The square root of 21901032 is about 4679.8538438716. The cubic root of 21901032 is about 279.7831313917.

Adding to 21901032 its reverse (23010912), we get a palindrome (44911944).

The spelling of 21901032 in words is "twenty-one million, nine hundred one thousand, thirty-two".