20851528785 has 16 divisors (see below), whose sum is σ = 33509422656. Its totient is φ = 11071823168.

The previous prime is 20851528783. The next prime is 20851528787. The reversal of 20851528785 is 58782515802.

It is an interprime number because it is at equal distance from previous prime (20851528783) and next prime (20851528787).

It is a cyclic number.

It is not a de Polignac number, because 20851528785 - 2¹ = 20851528783 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20851528783) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3058494 + ... + 3065303.

It is an arithmetic number, because the mean of its divisors is an integer number (2094338916).

Almost surely, 2^20851528785 is an apocalyptic number.

It is an amenable number.

20851528785 is a deficient number, since it is larger than the sum of its proper divisors (12657893871).

20851528785 is a wasteful number, since it uses less digits than its factorization.

20851528785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6124032.

The product of its (nonzero) digits is 1792000, while the sum is 51.

The spelling of 20851528785 in words is "twenty billion, eight hundred fifty-one million, five hundred twenty-eight thousand, seven hundred eighty-five".