20613128 has 8 divisors (see below), whose sum is σ = 38649630. Its totient is φ = 10306560.

The previous prime is 20613127. The next prime is 20613139. The reversal of 20613128 is 82131602.

It can be written as a sum of positive squares in only one way, i.e., 11957764 + 8655364 = 3458^2 + 2942^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (20613127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1288313 + ... + 1288328.

Almost surely, 2^20613128 is an apocalyptic number.

It is an amenable number.

20613128 is a deficient number, since it is larger than the sum of its proper divisors (18036502).

20613128 is a wasteful number, since it uses less digits than its factorization.

20613128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2576647 (or 2576643 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 20613128 is about 4540.1682788196. The cubic root of 20613128 is about 274.1876988368.

The spelling of 20613128 in words is "twenty million, six hundred thirteen thousand, one hundred twenty-eight".