126521440 has 48 divisors (see below), whose sum is σ = 299935440. Its totient is φ = 50434560.

The previous prime is 126521431. The next prime is 126521443. The reversal of 126521440 is 44125621.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (126521443) 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, 51766 + ... + 54154.

It is an arithmetic number, because the mean of its divisors is an integer number (6248655).

Almost surely, 2^126521440 is an apocalyptic number.

126521440 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 126521440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (149967720).

126521440 is an abundant number, since it is smaller than the sum of its proper divisors (173414000).

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

126521440 is a wasteful number, since it uses less digits than its factorization.

126521440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2735 (or 2727 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 126521440 is about 11248.1749630773. The cubic root of 126521440 is about 502.0204115445.

The spelling of 126521440 in words is "one hundred twenty-six million, five hundred twenty-one thousand, four hundred forty".