128561532 has 72 divisors (see below), whose sum is σ = 338779728. Its totient is φ = 37889280.

The previous prime is 128561483. The next prime is 128561539. The reversal of 128561532 is 235165821.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a junction number, because it is equal to n+sod(n) for n = 128561493 and 128561502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128561539) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 52528 + ... + 54920.

It is an arithmetic number, because the mean of its divisors is an integer number (4705274).

Almost surely, 2^128561532 is an apocalyptic number.

128561532 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 128561532, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (169389864).

128561532 is an abundant number, since it is smaller than the sum of its proper divisors (210218196).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

128561532 is a wasteful number, since it uses less digits than its factorization.

128561532 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2459 (or 2446 counting only the distinct ones).

The product of its digits is 14400, while the sum is 33.

The square root of 128561532 is about 11338.4977840982. The cubic root of 128561532 is about 504.7043094664.

The spelling of 128561532 in words is "one hundred twenty-eight million, five hundred sixty-one thousand, five hundred thirty-two".