21310140 has 48 divisors (see below), whose sum is σ = 60042528. Its totient is φ = 5647104.

The previous prime is 21310139. The next prime is 21310141. The reversal of 21310140 is 4101312.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21310139) and next prime (21310141).

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 (21310141) 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, 9354 + ... + 11406.

It is an arithmetic number, because the mean of its divisors is an integer number (1250886).

Almost surely, 2^21310140 is an apocalyptic number.

21310140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21310140 is an abundant number, since it is smaller than the sum of its proper divisors (38732388).

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

21310140 is a wasteful number, since it uses less digits than its factorization.

21310140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2238 (or 2236 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 21310140 is about 4616.2907187481. The cubic root of 21310140 is about 277.2439647997.

Adding to 21310140 its reverse (4101312), we get a palindrome (25411452).

The spelling of 21310140 in words is "twenty-one million, three hundred ten thousand, one hundred forty".