21341440 has 36 divisors (see below), whose sum is σ = 51122484. Its totient is φ = 8536064.

The previous prime is 21341407. The next prime is 21341479. The reversal of 21341440 is 4414312.

It can be written as a sum of positive squares in 2 ways, for example, as 14622976 + 6718464 = 3824^2 + 2592^2 .

It is a super-2 number, since 2×21341440² = 910914122547200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7057 + ... + 9616.

It is an arithmetic number, because the mean of its divisors is an integer number (1420069).

Almost surely, 2^21341440 is an apocalyptic number.

21341440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21341440 is an abundant number, since it is smaller than the sum of its proper divisors (29781044).

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

21341440 is an equidigital number, since it uses as much as digits as its factorization.

21341440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16694 (or 16680 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 21341440 is about 4619.6796425726. The cubic root of 21341440 is about 277.3796355959.

Adding to 21341440 its reverse (4414312), we get a palindrome (25755752).

The spelling of 21341440 in words is "twenty-one million, three hundred forty-one thousand, four hundred forty".