1655121311 has 4 divisors (see below), whose sum is σ = 1658808000. Its totient is φ = 1651434624.

The previous prime is 1655121287. The next prime is 1655121313. The reversal of 1655121311 is 1131215561.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1655121311 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1655121313) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1842671 + ... + 1843568.

It is an arithmetic number, because the mean of its divisors is an integer number (414702000).

Almost surely, 2^1655121311 is an apocalyptic number.

1655121311 is a deficient number, since it is larger than the sum of its proper divisors (3686689).

1655121311 is an equidigital number, since it uses as much as digits as its factorization.

1655121311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3686688.

The product of its digits is 900, while the sum is 26.

The square root of 1655121311 is about 40683.1821641326. The cubic root of 1655121311 is about 1182.8870489451.

Adding to 1655121311 its reverse (1131215561), we get a palindrome (2786336872).

The spelling of 1655121311 in words is "one billion, six hundred fifty-five million, one hundred twenty-one thousand, three hundred eleven".