21660770002 has 4 divisors (see below), whose sum is σ = 32491155006. Its totient is φ = 10830385000.

The previous prime is 21660769993. The next prime is 21660770003. The reversal of 21660770002 is 20007706612.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 20920440321 + 740329681 = 144639^2 + 27209^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (21660770003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5415192499 + ... + 5415192502.

Almost surely, 2^21660770002 is an apocalyptic number.

21660770002 is a deficient number, since it is larger than the sum of its proper divisors (10830385004).

21660770002 is a wasteful number, since it uses less digits than its factorization.

21660770002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10830385003.

The product of its (nonzero) digits is 7056, while the sum is 31.

The spelling of 21660770002 in words is "twenty-one billion, six hundred sixty million, seven hundred seventy thousand, two".