21247402 has 8 divisors (see below), whose sum is σ = 34768512. Its totient is φ = 9657900.

The previous prime is 21247393. The next prime is 21247411. The reversal of 21247402 is 20474212.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21247393) and next prime (21247411).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Harshad number since it is a multiple of its sum of digits (22), and also a Moran number because the ratio is a prime number: 965791 = 21247402 / (2 + 1 + 2 + 4 + 7 + 4 + 0 + 2).

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 482874 + ... + 482917.

It is an arithmetic number, because the mean of its divisors is an integer number (4346064).

Almost surely, 2^21247402 is an apocalyptic number.

21247402 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21247402 is a deficient number, since it is larger than the sum of its proper divisors (13521110).

21247402 is a wasteful number, since it uses less digits than its factorization.

21247402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 965804.

The product of its (nonzero) digits is 896, while the sum is 22.

The square root of 21247402 is about 4609.4904273683. The cubic root of 21247402 is about 276.9716245093.

The spelling of 21247402 in words is "twenty-one million, two hundred forty-seven thousand, four hundred two".