21239898265 has 8 divisors (see below), whose sum is σ = 26366770440. Its totient is φ = 16405990272.

The previous prime is 21239898257. The next prime is 21239898293. The reversal of 21239898265 is 56289893212.

It can be written as a sum of positive squares in 4 ways, for example, as 114147856 + 21125750409 = 10684^2 + 145347^2 .

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 21239898265 - 2³ = 21239898257 is a prime.

It is a super-2 number, since 2×21239898265² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 73240884 + ... + 73241173.

It is an arithmetic number, because the mean of its divisors is an integer number (3295846305).

Almost surely, 2^21239898265 is an apocalyptic number.

It is an amenable number.

21239898265 is a deficient number, since it is larger than the sum of its proper divisors (5126872175).

21239898265 is a wasteful number, since it uses less digits than its factorization.

21239898265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146482091.

The product of its digits is 3732480, while the sum is 55.

The spelling of 21239898265 in words is "twenty-one billion, two hundred thirty-nine million, eight hundred ninety-eight thousand, two hundred sixty-five".