21345443511 has 16 divisors (see below), whose sum is σ = 32530041600. Its totient is φ = 12196027008.

The previous prime is 21345443507. The next prime is 21345443563. The reversal of 21345443511 is 11534454312.

It is not a de Polignac number, because 21345443511 - 2² = 21345443507 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21345443311) 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, 152335 + ... + 256703.

It is an arithmetic number, because the mean of its divisors is an integer number (2033127600).

Almost surely, 2^21345443511 is an apocalyptic number.

21345443511 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21345443511 is a deficient number, since it is larger than the sum of its proper divisors (11184598089).

21345443511 is a wasteful number, since it uses less digits than its factorization.

21345443511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114118.

The product of its digits is 28800, while the sum is 33.

Adding to 21345443511 its reverse (11534454312), we get a palindrome (32879897823).

The spelling of 21345443511 in words is "twenty-one billion, three hundred forty-five million, four hundred forty-three thousand, five hundred eleven".