1405661121 has 10 divisors (see below), whose sum is σ = 2099814882. Its totient is φ = 937107360.

The previous prime is 1405661119. The next prime is 1405661129. The reversal of 1405661121 is 1211665041.

1405661121 is a `hidden beast` number, since 1 + 40 + 5 + 6 + 611 + 2 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1012194225 + 393466896 = 31815^2 + 19836^2 .

It is not a de Polignac number, because 1405661121 - 2¹ = 1405661119 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1405661129) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 8676840 + ... + 8677001.

Almost surely, 2^1405661121 is an apocalyptic number.

It is an amenable number.

1405661121 is a deficient number, since it is larger than the sum of its proper divisors (694153761).

1405661121 is an equidigital number, since it uses as much as digits as its factorization.

1405661121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17353853 (or 17353844 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 1405661121 is about 37492.1474578344. The cubic root of 1405661121 is about 1120.1947793148.

The spelling of 1405661121 in words is "one billion, four hundred five million, six hundred sixty-one thousand, one hundred twenty-one".