20156513 has 8 divisors (see below), whose sum is σ = 21743400. Its totient is φ = 18574848.

The previous prime is 20156501. The next prime is 20156519. The reversal of 20156513 is 31565102.

It can be written as a sum of positive squares in 4 ways, for example, as 238144 + 19918369 = 488^2 + 4463^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 20156513 - 2¹⁶ = 20090977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20156519) 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, 11243 + ... + 12911.

It is an arithmetic number, because the mean of its divisors is an integer number (2717925).

Almost surely, 2^20156513 is an apocalyptic number.

It is an amenable number.

20156513 is a deficient number, since it is larger than the sum of its proper divisors (1586887).

20156513 is a wasteful number, since it uses less digits than its factorization.

20156513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2611.

The product of its (nonzero) digits is 900, while the sum is 23.

The square root of 20156513 is about 4489.6005390235. The cubic root of 20156513 is about 272.1479920209.

The spelling of 20156513 in words is "twenty million, one hundred fifty-six thousand, five hundred thirteen".