21027137 has 16 divisors (see below), whose sum is σ = 22522752. Its totient is φ = 19601280.

The previous prime is 21027133. The next prime is 21027143. The reversal of 21027137 is 73172012.

It is not a de Polignac number, because 21027137 - 2² = 21027133 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21027131) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 125828 + ... + 125994.

It is an arithmetic number, because the mean of its divisors is an integer number (1407672).

Almost surely, 2^21027137 is an apocalyptic number.

It is an amenable number.

21027137 is a deficient number, since it is larger than the sum of its proper divisors (1495615).

21027137 is a wasteful number, since it uses less digits than its factorization.

21027137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 328.

The product of its (nonzero) digits is 588, while the sum is 23.

The square root of 21027137 is about 4585.5356284735. The cubic root of 21027137 is about 276.0112060492.

Adding to 21027137 its reverse (73172012), we get a palindrome (94199149).

The spelling of 21027137 in words is "twenty-one million, twenty-seven thousand, one hundred thirty-seven".