20851545 has 32 divisors (see below), whose sum is σ = 39199104. Its totient is φ = 9331200.

The previous prime is 20851541. The next prime is 20851549. The reversal of 20851545 is 54515802.

It is an interprime number because it is at equal distance from previous prime (20851541) and next prime (20851549).

It is not a de Polignac number, because 20851545 - 2² = 20851541 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20851541) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2716 + ... + 7005.

It is an arithmetic number, because the mean of its divisors is an integer number (1224972).

Almost surely, 2^20851545 is an apocalyptic number.

It is an amenable number.

20851545 is a deficient number, since it is larger than the sum of its proper divisors (18347559).

20851545 is a wasteful number, since it uses less digits than its factorization.

20851545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9753.

The product of its (nonzero) digits is 8000, while the sum is 30.

The square root of 20851545 is about 4566.3491982108. The cubic root of 20851545 is about 275.2407588543.

The spelling of 20851545 in words is "twenty million, eight hundred fifty-one thousand, five hundred forty-five".