21061139 has 12 divisors (see below), whose sum is σ = 24370920. Its totient is φ = 18136800.

The previous prime is 21061129. The next prime is 21061153. The reversal of 21061139 is 93116012.

It is a happy number.

It is not a de Polignac number, because 21061139 - 2⁸ = 21060883 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21061109) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 2282 + ... + 6879.

It is an arithmetic number, because the mean of its divisors is an integer number (2030910).

Almost surely, 2^21061139 is an apocalyptic number.

21061139 is a deficient number, since it is larger than the sum of its proper divisors (3309781).

21061139 is a wasteful number, since it uses less digits than its factorization.

21061139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9202 (or 9191 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 23.

The square root of 21061139 is about 4589.2416584878. The cubic root of 21061139 is about 276.1599008672.

The spelling of 21061139 in words is "twenty-one million, sixty-one thousand, one hundred thirty-nine".