61143449920 has 224 divisors, whose sum is σ = 168254281728. Its totient is φ = 20731133952.

The previous prime is 61143449897. The next prime is 61143449929. The reversal of 61143449920 is 2994434116.

It is a tau number, because it is divible by the number of its divisors (224).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61143449929) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 100730257 + ... + 100730863.

Almost surely, 2^61143449920 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 61143449920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (84127140864).

61143449920 is an abundant number, since it is smaller than the sum of its proper divisors (107110831808).

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

61143449920 is a wasteful number, since it uses less digits than its factorization.

61143449920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1057 (or 1047 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 43.

The spelling of 61143449920 in words is "sixty-one billion, one hundred forty-three million, four hundred forty-nine thousand, nine hundred twenty".