21540414 has 32 divisors (see below), whose sum is σ = 51828480. Its totient is φ = 5830272.

The previous prime is 21540383. The next prime is 21540437. The reversal of 21540414 is 41404512.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12699 + ... + 14294.

It is an arithmetic number, because the mean of its divisors is an integer number (1619640).

Almost surely, 2^21540414 is an apocalyptic number.

21540414 is an abundant number, since it is smaller than the sum of its proper divisors (30288066).

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

21540414 is a wasteful number, since it uses less digits than its factorization.

21540414 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27024.

The product of its (nonzero) digits is 640, while the sum is 21.

The square root of 21540414 is about 4641.1651554324. The cubic root of 21540414 is about 278.2390074033.

Adding to 21540414 its reverse (41404512), we get a palindrome (62944926).

The spelling of 21540414 in words is "twenty-one million, five hundred forty thousand, four hundred fourteen".