20400260666 has 4 divisors (see below), whose sum is σ = 30600391002. Its totient is φ = 10200130332.

The previous prime is 20400260633. The next prime is 20400260707. The reversal of 20400260666 is 66606200402.

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., 16074436225 + 4325824441 = 126785^2 + 65771^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5100065165 + ... + 5100065168.

Almost surely, 2^20400260666 is an apocalyptic number.

20400260666 is a deficient number, since it is larger than the sum of its proper divisors (10200130336).

20400260666 is a wasteful number, since it uses less digits than its factorization.

20400260666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10200130335.

The product of its (nonzero) digits is 20736, while the sum is 32.

The spelling of 20400260666 in words is "twenty billion, four hundred million, two hundred sixty thousand, six hundred sixty-six".