21311171546 has 16 divisors (see below), whose sum is σ = 36576086976. Its totient is φ = 9122696736.

The previous prime is 21311171509. The next prime is 21311171587. The reversal of 21311171546 is 64517111312.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 876116 + ... + 900111.

It is an arithmetic number, because the mean of its divisors is an integer number (2286005436).

Almost surely, 2^21311171546 is an apocalyptic number.

21311171546 is a deficient number, since it is larger than the sum of its proper divisors (15264915430).

21311171546 is a wasteful number, since it uses less digits than its factorization.

21311171546 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1777093.

The product of its digits is 5040, while the sum is 32.

Adding to 21311171546 its reverse (64517111312), we get a palindrome (85828282858).

The spelling of 21311171546 in words is "twenty-one billion, three hundred eleven million, one hundred seventy-one thousand, five hundred forty-six".