21239899395 has 256 divisors, whose sum is σ = 43243683840. Its totient is φ = 8758886400.

The previous prime is 21239899357. The next prime is 21239899403. The reversal of 21239899395 is 59399893212.

It is a happy number.

It is not a de Polignac number, because 21239899395 - 2¹¹ = 21239897347 is a prime.

It is a super-2 number, since 2×21239899395² (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 255 ways as a sum of consecutive naturals, for example, 218967987 + ... + 218968083.

It is an arithmetic number, because the mean of its divisors is an integer number (168920640).

Almost surely, 2^21239899395 is an apocalyptic number.

21239899395 is an abundant number, since it is smaller than the sum of its proper divisors (22003784445).

21239899395 is a wasteful number, since it uses less digits than its factorization.

21239899395 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 286.

The product of its digits is 9447840, while the sum is 60.

The spelling of 21239899395 in words is "twenty-one billion, two hundred thirty-nine million, eight hundred ninety-nine thousand, three hundred ninety-five".