61533240 has 64 divisors (see below), whose sum is σ = 186464160. Its totient is φ = 16243200.

The previous prime is 61533161. The next prime is 61533247. The reversal of 61533240 is 4233516.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 61533240.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61533247) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9582 + ... + 14658.

Almost surely, 2^61533240 is an apocalyptic number.

61533240 is a gapful number since it is divisible by the number (60) 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 61533240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (93232080).

61533240 is an abundant number, since it is smaller than the sum of its proper divisors (124930920).

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

61533240 is a wasteful number, since it uses less digits than its factorization.

61533240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5192 (or 5188 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 24.

The square root of 61533240 is about 7844.3125893860. The cubic root of 61533240 is about 394.7934400436.

Adding to 61533240 its reverse (4233516), we get a palindrome (65766756).

The spelling of 61533240 in words is "sixty-one million, five hundred thirty-three thousand, two hundred forty".