20506457875 has 16 divisors (see below), whose sum is σ = 26704761408. Its totient is φ = 15691896000.

The previous prime is 20506457857. The next prime is 20506457903. The reversal of 20506457875 is 57875460502.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-20506457875 is a prime.

It is a Duffinian 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, 3563466 + ... + 3569215.

It is an arithmetic number, because the mean of its divisors is an integer number (1669047588).

Almost surely, 2^20506457875 is an apocalyptic number.

20506457875 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

20506457875 is a deficient number, since it is larger than the sum of its proper divisors (6198303533).

20506457875 is an equidigital number, since it uses as much as digits as its factorization.

20506457875 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7132719 (or 7132709 counting only the distinct ones).

The product of its (nonzero) digits is 2352000, while the sum is 49.

The spelling of 20506457875 in words is "twenty billion, five hundred six million, four hundred fifty-seven thousand, eight hundred seventy-five".