61561202505 has 64 divisors (see below), whose sum is σ = 109186237440. Its totient is φ = 29369120000.

The previous prime is 61561202497. The next prime is 61561202513. The reversal of 61561202505 is 50520216516.

It is an interprime number because it is at equal distance from previous prime (61561202497) and next prime (61561202513).

It is not a de Polignac number, because 61561202505 - 2³ = 61561202497 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3428491 + ... + 3446399.

It is an arithmetic number, because the mean of its divisors is an integer number (1706034960).

Almost surely, 2^61561202505 is an apocalyptic number.

It is an amenable number.

61561202505 is a deficient number, since it is larger than the sum of its proper divisors (47625034935).

61561202505 is a wasteful number, since it uses less digits than its factorization.

61561202505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18262.

The product of its (nonzero) digits is 18000, while the sum is 33.

The spelling of 61561202505 in words is "sixty-one billion, five hundred sixty-one million, two hundred two thousand, five hundred five".