61405578 has 48 divisors (see below), whose sum is σ = 143857896. Its totient is φ = 18817920.

The previous prime is 61405541. The next prime is 61405579. The reversal of 61405578 is 87550416.

61405578 is a `hidden beast` number, since 61 + 40 + 557 + 8 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 54420129 + 6985449 = 7377^2 + 2643^2 .

It is not an unprimeable number, because it can be changed into a prime (61405579) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 92568 + ... + 93228.

Almost surely, 2^61405578 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61405578, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (71928948).

61405578 is an abundant number, since it is smaller than the sum of its proper divisors (82452318).

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

61405578 is a wasteful number, since it uses less digits than its factorization.

61405578 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1079 (or 1076 counting only the distinct ones).

The product of its (nonzero) digits is 33600, while the sum is 36.

The square root of 61405578 is about 7836.1711313626. The cubic root of 61405578 is about 394.5202271961.

The spelling of 61405578 in words is "sixty-one million, four hundred five thousand, five hundred seventy-eight".