20531601 has 12 divisors (see below), whose sum is σ = 29735940. Its totient is φ = 13651200.

The previous prime is 20531593. The next prime is 20531603. The reversal of 20531601 is 10613502.

It can be written as a sum of positive squares in 2 ways, for example, as 20034576 + 497025 = 4476^2 + 705^2 .

It is not a de Polignac number, because 20531601 - 2³ = 20531593 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20531603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 765 + ... + 6453.

It is an arithmetic number, because the mean of its divisors is an integer number (2477995).

Almost surely, 2^20531601 is an apocalyptic number.

It is an amenable number.

20531601 is a deficient number, since it is larger than the sum of its proper divisors (9204339).

20531601 is a wasteful number, since it uses less digits than its factorization.

20531601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6096 (or 6093 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 20531601 is about 4531.1809718880. The cubic root of 20531601 is about 273.8257412237.

The spelling of 20531601 in words is "twenty million, five hundred thirty-one thousand, six hundred one".