128520634 has 24 divisors (see below), whose sum is σ = 219218580. Its totient is φ = 56400960.

The previous prime is 128520631. The next prime is 128520643. The reversal of 128520634 is 436025821.

It can be written as a sum of positive squares in 2 ways, for example, as 126630009 + 1890625 = 11253^2 + 1375^2 .

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 128520596 and 128520605.

It is not an unprimeable number, because it can be changed into a prime (128520631) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2139 + ... + 16174.

Almost surely, 2^128520634 is an apocalyptic number.

128520634 is a deficient number, since it is larger than the sum of its proper divisors (90697946).

128520634 is a wasteful number, since it uses less digits than its factorization.

128520634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18366 (or 18355 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 31.

The square root of 128520634 is about 11336.6941389454. The cubic root of 128520634 is about 504.6507849382.

The spelling of 128520634 in words is "one hundred twenty-eight million, five hundred twenty thousand, six hundred thirty-four".