61399728 has 180 divisors, whose sum is σ = 197647320. Its totient is φ = 18240768.

The previous prime is 61399727. The next prime is 61399799. The reversal of 61399728 is 82799316.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

61399728 is a `hidden beast` number, since 613 + 9 + 9 + 7 + 28 = 666.

It is not an unprimeable number, because it can be changed into a prime (61399727) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 2117218 + ... + 2117246.

Almost surely, 2^61399728 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 61399728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (98823660).

61399728 is an abundant number, since it is smaller than the sum of its proper divisors (136247592).

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

61399728 is a wasteful number, since it uses less digits than its factorization.

61399728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101 (or 47 counting only the distinct ones).

The product of its digits is 163296, while the sum is 45.

The square root of 61399728 is about 7835.7978534416. The cubic root of 61399728 is about 394.5076983852.

The spelling of 61399728 in words is "sixty-one million, three hundred ninety-nine thousand, seven hundred twenty-eight".