661023220545042 has 16 divisors (see below), whose sum is σ = 1323343837020960. Its totient is φ = 220124840859872.

The previous prime is 661023220544977. The next prime is 661023220545101. The reversal of 661023220545042 is 240545022320166.

It is a junction number, because it is equal to n+sod(n) for n = 661023220544985 and 661023220545003.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 54058157163 + ... + 54058169390.

It is an arithmetic number, because the mean of its divisors is an integer number (82708989813810).

Almost surely, 2^{661023220545042} is an apocalyptic number.

661023220545042 is an abundant number, since it is smaller than the sum of its proper divisors (662320616475918).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661023220545042 is a wasteful number, since it uses less digits than its factorization.

661023220545042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108116327577.

The product of its (nonzero) digits is 691200, while the sum is 42.

The spelling of 661023220545042 in words is "six hundred sixty-one trillion, twenty-three billion, two hundred twenty million, five hundred forty-five thousand, forty-two".