20513157 has 8 divisors (see below), whose sum is σ = 31258176. Its totient is φ = 11721792.

The previous prime is 20513113. The next prime is 20513177. The reversal of 20513157 is 75131502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20513157 - 2⁶ = 20513093 is a prime.

It is a super-2 number, since 2×20513157² = 841579220213298, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20513177) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 488388 + ... + 488429.

It is an arithmetic number, because the mean of its divisors is an integer number (3907272).

Almost surely, 2^20513157 is an apocalyptic number.

It is an amenable number.

20513157 is a deficient number, since it is larger than the sum of its proper divisors (10745019).

20513157 is an equidigital number, since it uses as much as digits as its factorization.

20513157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 976827.

The product of its (nonzero) digits is 1050, while the sum is 24.

The square root of 20513157 is about 4529.1452836048. The cubic root of 20513157 is about 273.7437220470.

Adding to 20513157 its reverse (75131502), we get a palindrome (95644659).

The spelling of 20513157 in words is "twenty million, five hundred thirteen thousand, one hundred fifty-seven".