20510001 has 12 divisors (see below), whose sum is σ = 30256512. Its totient is φ = 13382136.

The previous prime is 20509981. The next prime is 20510027. The reversal of 20510001 is 10001502.

It is a happy number.

It is not a de Polignac number, because 20510001 - 2²² = 16315697 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20510071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 23821 + ... + 24666.

It is an arithmetic number, because the mean of its divisors is an integer number (2521376).

Almost surely, 2^20510001 is an apocalyptic number.

It is an amenable number.

20510001 is a deficient number, since it is larger than the sum of its proper divisors (9746511).

20510001 is a wasteful number, since it uses less digits than its factorization.

20510001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48540 (or 48537 counting only the distinct ones).

The product of its (nonzero) digits is 10, while the sum is 9.

The square root of 20510001 is about 4528.7968600943. The cubic root of 20510001 is about 273.7296826105.

Adding to 20510001 its reverse (10001502), we get a palindrome (30511503).

The spelling of 20510001 in words is "twenty million, five hundred ten thousand, one".