661121105 has 8 divisors (see below), whose sum is σ = 812695464. Its totient is φ = 515996800.

The previous prime is 661121101. The next prime is 661121119. The reversal of 661121105 is 501121166.

It can be written as a sum of positive squares in 4 ways, for example, as 14161 + 661106944 = 119^2 + 25712^2 .

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

It is not a de Polignac number, because 661121105 - 2² = 661121101 is a prime.

It is a super-2 number, since 2×661121105² = 874162230952842050, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661121101) 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, 1612286 + ... + 1612695.

It is an arithmetic number, because the mean of its divisors is an integer number (101586933).

Almost surely, 2^661121105 is an apocalyptic number.

It is an amenable number.

661121105 is a deficient number, since it is larger than the sum of its proper divisors (151574359).

661121105 is a wasteful number, since it uses less digits than its factorization.

661121105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3225027.

The product of its (nonzero) digits is 360, while the sum is 23.

The square root of 661121105 is about 25712.2753757811. The cubic root of 661121105 is about 871.1514699953.

The spelling of 661121105 in words is "six hundred sixty-one million, one hundred twenty-one thousand, one hundred five".