61511605 has 4 divisors (see below), whose sum is σ = 73813932. Its totient is φ = 49209280.

The previous prime is 61511573. The next prime is 61511621. The reversal of 61511605 is 50611516.

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 23059204 + 38452401 = 4802^2 + 6201^2 .

It is not a de Polignac number, because 61511605 - 2⁵ = 61511573 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 61511605.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6151156 + ... + 6151165.

It is an arithmetic number, because the mean of its divisors is an integer number (18453483).

Almost surely, 2^61511605 is an apocalyptic number.

It is an amenable number.

61511605 is a deficient number, since it is larger than the sum of its proper divisors (12302327).

61511605 is a wasteful number, since it uses less digits than its factorization.

61511605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12302326.

The product of its (nonzero) digits is 900, while the sum is 25.

The square root of 61511605 is about 7842.9334435529. The cubic root of 61511605 is about 394.7471650150.

The spelling of 61511605 in words is "sixty-one million, five hundred eleven thousand, six hundred five".