61511152240 has 80 divisors (see below), whose sum is σ = 147349819008. Its totient is φ = 23867691008.

The previous prime is 61511152231. The next prime is 61511152243. The reversal of 61511152240 is 4225111516.

It is a tau number, because it is divible by the number of its divisors (80).

It is a junction number, because it is equal to n+sod(n) for n = 61511152199 and 61511152208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61511152243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 352494 + ... + 497266.

Almost surely, 2^61511152240 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61511152240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (73674909504).

61511152240 is an abundant number, since it is smaller than the sum of its proper divisors (85838666768).

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

61511152240 is a wasteful number, since it uses less digits than its factorization.

61511152240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144946 (or 144940 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 28.

Adding to 61511152240 its reverse (4225111516), we get a palindrome (65736263756).

The spelling of 61511152240 in words is "sixty-one billion, five hundred eleven million, one hundred fifty-two thousand, two hundred forty".