21073139 has 8 divisors (see below), whose sum is σ = 22090992. Its totient is φ = 20079360.

The previous prime is 21073127. The next prime is 21073141. The reversal of 21073139 is 93137012.

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 21073139 - 2²⁴ = 4295923 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21073159) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4214 + ... + 7739.

It is an arithmetic number, because the mean of its divisors is an integer number (2761374).

Almost surely, 2^21073139 is an apocalyptic number.

21073139 is a deficient number, since it is larger than the sum of its proper divisors (1017853).

21073139 is a wasteful number, since it uses less digits than its factorization.

21073139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12037.

The product of its (nonzero) digits is 1134, while the sum is 26.

The square root of 21073139 is about 4590.5488778576. The cubic root of 21073139 is about 276.2123400953.

It can be divided in two parts, 21073 and 139, that added together give a palindrome (21212).

The spelling of 21073139 in words is "twenty-one million, seventy-three thousand, one hundred thirty-nine".