21040234345 has 48 divisors (see below), whose sum is σ = 28833779520. Its totient is φ = 14611224960.

The previous prime is 21040234301. The next prime is 21040234349. The reversal of 21040234345 is 54343204012.

It is a happy number.

It is not a de Polignac number, because 21040234345 - 2³³ = 12450299753 is a prime.

It is a super-2 number, since 2×21040234345² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21040234349) by changing a digit.

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 47 ways as a sum of consecutive naturals, for example, 45053802 + ... + 45054268.

It is an arithmetic number, because the mean of its divisors is an integer number (600703740).

Almost surely, 2^21040234345 is an apocalyptic number.

It is an amenable number.

21040234345 is a deficient number, since it is larger than the sum of its proper divisors (7793545175).

21040234345 is a wasteful number, since it uses less digits than its factorization.

21040234345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 886 (or 695 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 28.

Adding to 21040234345 its reverse (54343204012), we get a palindrome (75383438357).

The spelling of 21040234345 in words is "twenty-one billion, forty million, two hundred thirty-four thousand, three hundred forty-five".