61323440 has 20 divisors (see below), whose sum is σ = 142577184. Its totient is φ = 24529344.

The previous prime is 61323421. The next prime is 61323443. The reversal of 61323440 is 4432316.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (20).

It is not an unprimeable number, because it can be changed into a prime (61323443) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 383192 + ... + 383351.

Almost surely, 2^61323440 is an apocalyptic number.

It is an amenable number.

61323440 is an abundant number, since it is smaller than the sum of its proper divisors (81253744).

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

61323440 is a wasteful number, since it uses less digits than its factorization.

61323440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 766556 (or 766550 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 23.

The square root of 61323440 is about 7830.9284251613. The cubic root of 61323440 is about 394.3442412194.

Adding to 61323440 its reverse (4432316), we get a palindrome (65755756).

The spelling of 61323440 in words is "sixty-one million, three hundred twenty-three thousand, four hundred forty".