61499520 has 128 divisors (see below), whose sum is σ = 217872000. Its totient is φ = 16395264.

The previous prime is 61499519. The next prime is 61499527. The reversal of 61499520 is 2599416.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (61499527) 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, 15501 + ... + 19059.

It is an arithmetic number, because the mean of its divisors is an integer number (1702125).

Almost surely, 2^61499520 is an apocalyptic number.

61499520 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 61499520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108936000).

61499520 is an abundant number, since it is smaller than the sum of its proper divisors (156372480).

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

61499520 is a wasteful number, since it uses less digits than its factorization.

61499520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3587 (or 3569 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The square root of 61499520 is about 7842.1629669371. The cubic root of 61499520 is about 394.7213117258.

The spelling of 61499520 in words is "sixty-one million, four hundred ninety-nine thousand, five hundred twenty".