21068497487 has 16 divisors (see below), whose sum is σ = 21896404992. Its totient is φ = 20255508000.

The previous prime is 21068497469. The next prime is 21068497501. The reversal of 21068497487 is 78479486012.

It is a cyclic number.

It is not a de Polignac number, because 21068497487 - 2⁸ = 21068497231 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21068497447) 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, 1170518 + ... + 1188380.

It is an arithmetic number, because the mean of its divisors is an integer number (1368525312).

Almost surely, 2^21068497487 is an apocalyptic number.

21068497487 is a deficient number, since it is larger than the sum of its proper divisors (827907505).

21068497487 is a wasteful number, since it uses less digits than its factorization.

21068497487 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18278.

The product of its (nonzero) digits is 5419008, while the sum is 56.

The spelling of 21068497487 in words is "twenty-one billion, sixty-eight million, four hundred ninety-seven thousand, four hundred eighty-seven".