61306405 has 4 divisors (see below), whose sum is σ = 73567692. Its totient is φ = 49045120.

The previous prime is 61306397. The next prime is 61306409. The reversal of 61306405 is 50460316.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 36216324 + 25090081 = 6018^2 + 5009^2 .

It is not a de Polignac number, because 61306405 - 2³ = 61306397 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 61306405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61306409) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6130636 + ... + 6130645.

It is an arithmetic number, because the mean of its divisors is an integer number (18391923).

Almost surely, 2^61306405 is an apocalyptic number.

It is an amenable number.

61306405 is a deficient number, since it is larger than the sum of its proper divisors (12261287).

61306405 is a wasteful number, since it uses less digits than its factorization.

61306405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12261286.

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 61306405 is about 7829.8406752628. The cubic root of 61306405 is about 394.3077229578.

The spelling of 61306405 in words is "sixty-one million, three hundred six thousand, four hundred five".