123521440 has 96 divisors (see below), whose sum is σ = 345098880. Its totient is φ = 40879104.

The previous prime is 123521423. The next prime is 123521441. The reversal of 123521440 is 44125321.

It is a super-2 number, since 2×123521440² = 30515092279347200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (123521441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30579 + ... + 34381.

It is an arithmetic number, because the mean of its divisors is an integer number (3594780).

Almost surely, 2^123521440 is an apocalyptic number.

123521440 is a gapful number since it is divisible by the number (10) 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 123521440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (172549440).

123521440 is an abundant number, since it is smaller than the sum of its proper divisors (221577440).

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

123521440 is a wasteful number, since it uses less digits than its factorization.

123521440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3854 (or 3846 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 123521440 is about 11114.0199747886. The cubic root of 123521440 is about 498.0207622404.

Adding to 123521440 its reverse (44125321), we get a palindrome (167646761).

The spelling of 123521440 in words is "one hundred twenty-three million, five hundred twenty-one thousand, four hundred forty".