20566667997 has 6 divisors (see below), whose sum is σ = 29707409342. Its totient is φ = 13711111992.

The previous prime is 20566667981. The next prime is 20566668013. The reversal of 20566667997 is 79976666502.

It is an interprime number because it is at equal distance from previous prime (20566667981) and next prime (20566668013).

It can be written as a sum of positive squares in only one way, i.e., 19449370521 + 1117297476 = 139461^2 + 33426^2 .

It is not a de Polignac number, because 20566667997 - 2⁴ = 20566667981 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 (20566667917) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1142592658 + ... + 1142592675.

Almost surely, 2^20566667997 is an apocalyptic number.

It is an amenable number.

20566667997 is a deficient number, since it is larger than the sum of its proper divisors (9140741345).

20566667997 is a wasteful number, since it uses less digits than its factorization.

20566667997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2285185339 (or 2285185336 counting only the distinct ones).

The product of its (nonzero) digits is 51438240, while the sum is 63.

The spelling of 20566667997 in words is "twenty billion, five hundred sixty-six million, six hundred sixty-seven thousand, nine hundred ninety-seven".