20513207 has 16 divisors (see below), whose sum is σ = 24757152. Its totient is φ = 16744320.

The previous prime is 20513191. The next prime is 20513231. The reversal of 20513207 is 70231502.

It is a cyclic number.

It is not a de Polignac number, because 20513207 - 2⁴ = 20513191 is a prime.

It is a super-2 number, since 2×20513207² = 841583322849698, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20513257) 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, 3353 + ... + 7229.

It is an arithmetic number, because the mean of its divisors is an integer number (1547322).

Almost surely, 2^20513207 is an apocalyptic number.

20513207 is a deficient number, since it is larger than the sum of its proper divisors (4243945).

20513207 is a wasteful number, since it uses less digits than its factorization.

20513207 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3938.

The product of its (nonzero) digits is 420, while the sum is 20.

The square root of 20513207 is about 4529.1508034067. The cubic root of 20513207 is about 273.7439444599.

Adding to 20513207 its reverse (70231502), we get a palindrome (90744709).

The spelling of 20513207 in words is "twenty million, five hundred thirteen thousand, two hundred seven".