21036743 has 32 divisors (see below), whose sum is σ = 28492800. Its totient is φ = 15082848.

The previous prime is 21036737. The next prime is 21036749. The reversal of 21036743 is 34763012.

It is an interprime number because it is at equal distance from previous prime (21036737) and next prime (21036749).

It is not a de Polignac number, because 21036743 - 2¹² = 21032647 is a prime.

It is a hoax number, since the sum of its digits (26) coincides with the sum of the digits of its distinct prime factors.

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

It is a taxicab number since it can be written as a sum of two cubes in more than one way. Here 21036743 = 23³ + 276³ = 207³ + 230³.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21036749) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 914630 + ... + 914652.

It is an arithmetic number, because the mean of its divisors is an integer number (890400).

Almost surely, 2^21036743 is an apocalyptic number.

21036743 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21036743 is a deficient number, since it is larger than the sum of its proper divisors (7456057).

21036743 is an equidigital number, since it uses as much as digits as its factorization.

21036743 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108 (or 62 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 26.

The square root of 21036743 is about 4586.5829328597. The cubic root of 21036743 is about 276.0532304738.

Adding to 21036743 its reverse (34763012), we get a palindrome (55799755).

The spelling of 21036743 in words is "twenty-one million, thirty-six thousand, seven hundred forty-three".