1663211121 has 64 divisors (see below), whose sum is σ = 2765629440. Its totient is φ = 874621440.

The previous prime is 1663211063. The next prime is 1663211153. The reversal of 1663211121 is 1211123661.

It is a happy number.

It is not a de Polignac number, because 1663211121 - 2⁹ = 1663210609 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1663211091 and 1663211100.

It is not an unprimeable number, because it can be changed into a prime (1663211171) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 580725 + ... + 583581.

It is an arithmetic number, because the mean of its divisors is an integer number (43212960).

Almost surely, 2^1663211121 is an apocalyptic number.

1663211121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1663211121 is a deficient number, since it is larger than the sum of its proper divisors (1102418319).

1663211121 is a wasteful number, since it uses less digits than its factorization.

1663211121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2966.

The product of its digits is 432, while the sum is 24.

The square root of 1663211121 is about 40782.4854686421. The cubic root of 1663211121 is about 1184.8111340653.

Adding to 1663211121 its reverse (1211123661), we get a palindrome (2874334782).

The spelling of 1663211121 in words is "one billion, six hundred sixty-three million, two hundred eleven thousand, one hundred twenty-one".