21512541345 has 16 divisors (see below), whose sum is σ = 34446635520. Its totient is φ = 11464498944.

The previous prime is 21512541317. The next prime is 21512541367. The reversal of 21512541345 is 54314521512.

It is not a de Polignac number, because 21512541345 - 2¹⁴ = 21512524961 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 533425 + ... + 572334.

It is an arithmetic number, because the mean of its divisors is an integer number (2152914720).

Almost surely, 2^21512541345 is an apocalyptic number.

It is an amenable number.

21512541345 is a deficient number, since it is larger than the sum of its proper divisors (12934094175).

21512541345 is a wasteful number, since it uses less digits than its factorization.

21512541345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1107064.

The product of its digits is 24000, while the sum is 33.

The spelling of 21512541345 in words is "twenty-one billion, five hundred twelve million, five hundred forty-one thousand, three hundred forty-five".