20641262545 has 4 divisors (see below), whose sum is σ = 24769515060. Its totient is φ = 16513010032.

The previous prime is 20641262539. The next prime is 20641262567. The reversal of 20641262545 is 54526214602.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 12218428369 + 8422834176 = 110537^2 + 91776^2 .

It is a cyclic number.

It is not a de Polignac number, because 20641262545 - 2⁷ = 20641262417 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2064126250 + ... + 2064126259.

It is an arithmetic number, because the mean of its divisors is an integer number (6192378765).

Almost surely, 2^20641262545 is an apocalyptic number.

It is an amenable number.

20641262545 is a deficient number, since it is larger than the sum of its proper divisors (4128252515).

20641262545 is an equidigital number, since it uses as much as digits as its factorization.

20641262545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4128252514.

The product of its (nonzero) digits is 115200, while the sum is 37.

The spelling of 20641262545 in words is "twenty billion, six hundred forty-one million, two hundred sixty-two thousand, five hundred forty-five".