21027743 has 6 divisors (see below), whose sum is σ = 23113272. Its totient is φ = 19116020.

The previous prime is 21027709. The next prime is 21027767. The reversal of 21027743 is 34772012.

It is not a de Polignac number, because 21027743 - 2⁶ = 21027679 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21027143) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 86771 + ... + 87012.

It is an arithmetic number, because the mean of its divisors is an integer number (3852212).

Almost surely, 2^21027743 is an apocalyptic number.

21027743 is a deficient number, since it is larger than the sum of its proper divisors (2085529).

21027743 is a wasteful number, since it uses less digits than its factorization.

21027743 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173805 (or 173794 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 26.

The square root of 21027743 is about 4585.6017053381. The cubic root of 21027743 is about 276.0138575623.

Adding to 21027743 its reverse (34772012), we get a palindrome (55799755).

The spelling of 21027743 in words is "twenty-one million, twenty-seven thousand, seven hundred forty-three".