61540405 has 8 divisors (see below), whose sum is σ = 74112984. Its totient is φ = 49056000.

The previous prime is 61540403. The next prime is 61540417. The reversal of 61540405 is 50404516.

It can be written as a sum of positive squares in 4 ways, for example, as 10817521 + 50722884 = 3289^2 + 7122^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 61540405 - 2¹ = 61540403 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 61540405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61540403) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20496 + ... + 23305.

It is an arithmetic number, because the mean of its divisors is an integer number (9264123).

Almost surely, 2^61540405 is an apocalyptic number.

It is an amenable number.

61540405 is a deficient number, since it is larger than the sum of its proper divisors (12572579).

61540405 is a wasteful number, since it uses less digits than its factorization.

61540405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44087.

The product of its (nonzero) digits is 2400, while the sum is 25.

The square root of 61540405 is about 7844.7692764032. The cubic root of 61540405 is about 394.8087628470.

The spelling of 61540405 in words is "sixty-one million, five hundred forty thousand, four hundred five".