21240370727 has 8 divisors (see below), whose sum is σ = 21297512880. Its totient is φ = 21183261120.

The previous prime is 21240370709. The next prime is 21240370729. The reversal of 21240370727 is 72707304212.

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 21240370727 - 2⁶ = 21240370663 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 (21240370729) 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, 1850468 + ... + 1861910.

It is an arithmetic number, because the mean of its divisors is an integer number (2662189110).

Almost surely, 2^21240370727 is an apocalyptic number.

21240370727 is a deficient number, since it is larger than the sum of its proper divisors (57142153).

21240370727 is a wasteful number, since it uses less digits than its factorization.

21240370727 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16273.

The product of its (nonzero) digits is 32928, while the sum is 35.

Adding to 21240370727 its reverse (72707304212), we get a palindrome (93947674939).

The spelling of 21240370727 in words is "twenty-one billion, two hundred forty million, three hundred seventy thousand, seven hundred twenty-seven".