61561020111 has 8 divisors (see below), whose sum is σ = 83426956464. Its totient is φ = 40367881920.

The previous prime is 61561020107. The next prime is 61561020119. The reversal of 61561020111 is 11102016516.

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

It is not a de Polignac number, because 61561020111 - 2² = 61561020107 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61561020119) 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, 168199326 + ... + 168199691.

It is an arithmetic number, because the mean of its divisors is an integer number (10428369558).

Almost surely, 2^61561020111 is an apocalyptic number.

61561020111 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

61561020111 is a deficient number, since it is larger than the sum of its proper divisors (21865936353).

61561020111 is a wasteful number, since it uses less digits than its factorization.

61561020111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 336399081.

The product of its (nonzero) digits is 360, while the sum is 24.

Adding to 61561020111 its reverse (11102016516), we get a palindrome (72663036627).

The spelling of 61561020111 in words is "sixty-one billion, five hundred sixty-one million, twenty thousand, one hundred eleven".