21340144 has 20 divisors (see below), whose sum is σ = 47253424. Its totient is φ = 9145728.

The previous prime is 21340141. The next prime is 21340147. The reversal of 21340144 is 44104312.

It is an interprime number because it is at equal distance from previous prime (21340141) and next prime (21340147).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21340141) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 95157 + ... + 95380.

Almost surely, 2^21340144 is an apocalyptic number.

It is an amenable number.

21340144 is an abundant number, since it is smaller than the sum of its proper divisors (25913280).

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

21340144 is a wasteful number, since it uses less digits than its factorization.

21340144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 190552 (or 190546 counting only the distinct ones).

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

The square root of 21340144 is about 4619.5393709763. The cubic root of 21340144 is about 277.3740206783.

Adding to 21340144 its reverse (44104312), we get a palindrome (65444456).

The spelling of 21340144 in words is "twenty-one million, three hundred forty thousand, one hundred forty-four".