21214740 has 48 divisors (see below), whose sum is σ = 61987968. Its totient is φ = 5410944.

The previous prime is 21214703. The next prime is 21214741. The reversal of 21214740 is 4741212.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21214741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6307 + ... + 9066.

It is an arithmetic number, because the mean of its divisors is an integer number (1291416).

Almost surely, 2^21214740 is an apocalyptic number.

21214740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21214740 is an abundant number, since it is smaller than the sum of its proper divisors (40773228).

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

21214740 is a wasteful number, since it uses less digits than its factorization.

21214740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15408 (or 15406 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 21.

The square root of 21214740 is about 4605.9461568716. The cubic root of 21214740 is about 276.8296293196.

Adding to 21214740 its reverse (4741212), we get a palindrome (25955952).

The spelling of 21214740 in words is "twenty-one million, two hundred fourteen thousand, seven hundred forty".