61605138 has 64 divisors (see below), whose sum is σ = 145262592. Its totient is φ = 17055360.

The previous prime is 61605113. The next prime is 61605169. The reversal of 61605138 is 83150616.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 217545 + ... + 217827.

It is an arithmetic number, because the mean of its divisors is an integer number (2269728).

Almost surely, 2^61605138 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61605138, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (72631296).

61605138 is an abundant number, since it is smaller than the sum of its proper divisors (83657454).

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

61605138 is a wasteful number, since it uses less digits than its factorization.

61605138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 439.

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 61605138 is about 7848.8940622230. The cubic root of 61605138 is about 394.9471445593.

The spelling of 61605138 in words is "sixty-one million, six hundred five thousand, one hundred thirty-eight".