21660701606 has 16 divisors (see below), whose sum is σ = 34433710416. Its totient is φ = 10183961856.

The previous prime is 21660701581. The next prime is 21660701639. The reversal of 21660701606 is 60610706612.

It is a congruent number.

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, 253076 + ... + 327671.

It is an arithmetic number, because the mean of its divisors is an integer number (2152106901).

Almost surely, 2^21660701606 is an apocalyptic number.

21660701606 is a deficient number, since it is larger than the sum of its proper divisors (12773008810).

21660701606 is a wasteful number, since it uses less digits than its factorization.

21660701606 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 581863.

The product of its (nonzero) digits is 18144, while the sum is 35.

The spelling of 21660701606 in words is "twenty-one billion, six hundred sixty million, seven hundred one thousand, six hundred six".