20678241565 has 16 divisors (see below), whose sum is σ = 25219283760. Its totient is φ = 16274419200.

The previous prime is 20678241527. The next prime is 20678241593. The reversal of 20678241565 is 56514287602.

It can be written as a sum of positive squares in 8 ways, for example, as 278689636 + 20399551929 = 16694^2 + 142827^2 .

It is a de Polignac number, because none of the positive numbers 2^k-20678241565 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 51120 + ... + 209689.

It is an arithmetic number, because the mean of its divisors is an integer number (1576205235).

Almost surely, 2^20678241565 is an apocalyptic number.

It is an amenable number.

20678241565 is a deficient number, since it is larger than the sum of its proper divisors (4541042195).

20678241565 is a wasteful number, since it uses less digits than its factorization.

20678241565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 261072.

The product of its (nonzero) digits is 806400, while the sum is 46.

The spelling of 20678241565 in words is "twenty billion, six hundred seventy-eight million, two hundred forty-one thousand, five hundred sixty-five".