661205045 has 16 divisors (see below), whose sum is σ = 821076480. Its totient is φ = 510628800.

The previous prime is 661205011. The next prime is 661205093. The reversal of 661205045 is 540502166.

It is not a de Polignac number, because 661205045 - 2⁶ = 661204981 is a prime.

It is a super-2 number, since 2×661205045² = 874384223066904050, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 661204999 and 661205017.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 59855 + ... + 70035.

It is an arithmetic number, because the mean of its divisors is an integer number (51317280).

Almost surely, 2^661205045 is an apocalyptic number.

It is an amenable number.

661205045 is a deficient number, since it is larger than the sum of its proper divisors (159871435).

661205045 is a wasteful number, since it uses less digits than its factorization.

661205045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10636.

The product of its (nonzero) digits is 7200, while the sum is 29.

The square root of 661205045 is about 25713.9076182520. The cubic root of 661205045 is about 871.1883373505.

The spelling of 661205045 in words is "six hundred sixty-one million, two hundred five thousand, forty-five".