61515670561 has 4 divisors (see below), whose sum is σ = 61516773252. Its totient is φ = 61514567872.

The previous prime is 61515670553. The next prime is 61515670583. The reversal of 61515670561 is 16507651516.

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 830304225 + 60685366336 = 28815^2 + 246344^2 .

It is a cyclic number.

It is not a de Polignac number, because 61515670561 - 2³ = 61515670553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61515670861) 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, 462940 + ... + 580813.

It is an arithmetic number, because the mean of its divisors is an integer number (15379193313).

Almost surely, 2^61515670561 is an apocalyptic number.

It is an amenable number.

61515670561 is a deficient number, since it is larger than the sum of its proper divisors (1102691).

61515670561 is a wasteful number, since it uses less digits than its factorization.

61515670561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1102690.

The product of its (nonzero) digits is 189000, while the sum is 43.

The spelling of 61515670561 in words is "sixty-one billion, five hundred fifteen million, six hundred seventy thousand, five hundred sixty-one".