21292743 has 8 divisors (see below), whose sum is σ = 28499328. Its totient is φ = 14140664.

The previous prime is 21292729. The next prime is 21292751. The reversal of 21292743 is 34729212.

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

It is a cyclic number.

It is not a de Polignac number, because 21292743 - 2⁸ = 21292487 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a self number, because there is not a number n which added to its sum of digits gives 21292743.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21292343) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 12705 + ... + 14282.

It is an arithmetic number, because the mean of its divisors is an integer number (3562416).

Almost surely, 2^21292743 is an apocalyptic number.

21292743 is a deficient number, since it is larger than the sum of its proper divisors (7206585).

21292743 is a wasteful number, since it uses less digits than its factorization.

21292743 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27253.

The product of its digits is 6048, while the sum is 30.

The square root of 21292743 is about 4614.4060289489. The cubic root of 21292743 is about 277.1684995303.

The spelling of 21292743 in words is "twenty-one million, two hundred ninety-two thousand, seven hundred forty-three".