21130340 has 48 divisors (see below), whose sum is σ = 55327104. Its totient is φ = 6585600.

The previous prime is 21130331. The next prime is 21130397. The reversal of 21130340 is 4303112.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5321 + ... + 8400.

It is an arithmetic number, because the mean of its divisors is an integer number (1152648).

Almost surely, 2^21130340 is an apocalyptic number.

21130340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21130340 is an abundant number, since it is smaller than the sum of its proper divisors (34196764).

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

21130340 is a wasteful number, since it uses less digits than its factorization.

21130340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13748 (or 13746 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 21130340 is about 4596.7749564233. The cubic root of 21130340 is about 276.4620315480.

Adding to 21130340 its reverse (4303112), we get a palindrome (25433452).

The spelling of 21130340 in words is "twenty-one million, one hundred thirty thousand, three hundred forty".