61027721775 has 18 divisors (see below), whose sum is σ = 109307430960. Its totient is φ = 32548118160.

The previous prime is 61027721723. The next prime is 61027721789. The reversal of 61027721775 is 57712772016.

61027721775 is a `hidden beast` number, since 610 + 2 + 7 + 7 + 21 + 7 + 7 + 5 = 666.

It is not a de Polignac number, because 61027721775 - 2⁸ = 61027721519 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 61027721775.

It is a congruent number.

It is an unprimeable number.

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 17 ways as a sum of consecutive naturals, for example, 135616935 + ... + 135617384.

Almost surely, 2^61027721775 is an apocalyptic number.

61027721775 is a deficient number, since it is larger than the sum of its proper divisors (48279709185).

61027721775 is a wasteful number, since it uses less digits than its factorization.

61027721775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 271234335 (or 271234327 counting only the distinct ones).

The product of its (nonzero) digits is 288120, while the sum is 45.

The spelling of 61027721775 in words is "sixty-one billion, twenty-seven million, seven hundred twenty-one thousand, seven hundred seventy-five".