20415660561365 has 8 divisors (see below), whose sum is σ = 24506408108760. Its totient is φ = 16327451492352.

The previous prime is 20415660561277. The next prime is 20415660561371. The reversal of 20415660561365 is 56316506651402.

It can be written as a sum of positive squares in 4 ways, for example, as 3236235494116 + 17179425067249 = 1798954^2 + 4144807^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20415660561365 - 2³⁶ = 20346941084629 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 634601900 + ... + 634634069.

It is an arithmetic number, because the mean of its divisors is an integer number (3063301013595).

Almost surely, 2^{20415660561365} is an apocalyptic number.

It is an amenable number.

20415660561365 is a deficient number, since it is larger than the sum of its proper divisors (4090747547395).

20415660561365 is a wasteful number, since it uses less digits than its factorization.

20415660561365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1269239191.

The product of its (nonzero) digits is 3888000, while the sum is 50.

The spelling of 20415660561365 in words is "twenty trillion, four hundred fifteen billion, six hundred sixty million, five hundred sixty-one thousand, three hundred sixty-five".