21351246006243 has 32 divisors (see below), whose sum is σ = 29040462662400. Its totient is φ = 13948754158976.

The previous prime is 21351246006241. The next prime is 21351246006253. The reversal of 21351246006243 is 34260064215312.

It is a cyclic number.

It is not a de Polignac number, because 21351246006243 - 2¹ = 21351246006241 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21351246006241) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 516246121 + ... + 516287477.

It is an arithmetic number, because the mean of its divisors is an integer number (907514458200).

Almost surely, 2^{21351246006243} is an apocalyptic number.

21351246006243 is a deficient number, since it is larger than the sum of its proper divisors (7689216656157).

21351246006243 is a wasteful number, since it uses less digits than its factorization.

21351246006243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45251.

The product of its (nonzero) digits is 207360, while the sum is 39.

The spelling of 21351246006243 in words is "twenty-one trillion, three hundred fifty-one billion, two hundred forty-six million, six thousand, two hundred forty-three".