21062739 has 4 divisors (see below), whose sum is σ = 28083656. Its totient is φ = 14041824.

The previous prime is 21062737. The next prime is 21062747. The reversal of 21062739 is 93726012.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21062739 - 2¹ = 21062737 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21062737) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3510454 + ... + 3510459.

It is an arithmetic number, because the mean of its divisors is an integer number (7020914).

Almost surely, 2^21062739 is an apocalyptic number.

21062739 is a deficient number, since it is larger than the sum of its proper divisors (7020917).

21062739 is an equidigital number, since it uses as much as digits as its factorization.

21062739 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7020916.

The product of its (nonzero) digits is 4536, while the sum is 30.

The square root of 21062739 is about 4589.4159759168. The cubic root of 21062739 is about 276.1668939149.

The spelling of 21062739 in words is "twenty-one million, sixty-two thousand, seven hundred thirty-nine".