21130032 has 80 divisors (see below), whose sum is σ = 68067072. Its totient is φ = 5487360.

The previous prime is 21130027. The next prime is 21130037. The reversal of 21130032 is 23003112.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21130027) and next prime (21130037).

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21130037) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 838 + ... + 6554.

Almost surely, 2^21130032 is an apocalyptic number.

21130032 is a gapful number since it is divisible by the number (22) 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 21130032, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34033536).

21130032 is an abundant number, since it is smaller than the sum of its proper divisors (46937040).

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

21130032 is a wasteful number, since it uses less digits than its factorization.

21130032 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5746 (or 5740 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 12.

The square root of 21130032 is about 4596.7414545523. The cubic root of 21130032 is about 276.4606882864.

Adding to 21130032 its reverse (23003112), we get a palindrome (44133144).

Subtracting 21130032 from its reverse (23003112), we obtain a triangular number (1873080 = T₁₉₃₅).

The spelling of 21130032 in words is "twenty-one million, one hundred thirty thousand, thirty-two".