61011511665 has 64 divisors (see below), whose sum is σ = 105652780800. Its totient is φ = 29886796800.

The previous prime is 61011511661. The next prime is 61011511697. The reversal of 61011511665 is 56611511016.

It is not a de Polignac number, because 61011511665 - 2² = 61011511661 is a prime.

It is not an unprimeable number, because it can be changed into a prime (61011511661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 58050390 + ... + 58051440.

It is an arithmetic number, because the mean of its divisors is an integer number (1650824700).

Almost surely, 2^61011511665 is an apocalyptic number.

61011511665 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

61011511665 is a deficient number, since it is larger than the sum of its proper divisors (44641269135).

61011511665 is a wasteful number, since it uses less digits than its factorization.

61011511665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2274.

The product of its (nonzero) digits is 5400, while the sum is 33.

The spelling of 61011511665 in words is "sixty-one billion, eleven million, five hundred eleven thousand, six hundred sixty-five".