1655220331 has 2 divisors, whose sum is σ = 1655220332. Its totient is φ = 1655220330.

The previous prime is 1655220313. The next prime is 1655220341. The reversal of 1655220331 is 1330225561.

Together with previous prime (1655220313) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1655220331 - 2²⁷ = 1521002603 is a prime.

It is a super-2 number, since 2×1655220331² = 5479508688311499122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1655220331.

It is not a weakly prime, because it can be changed into another prime (1655220341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 827610165 + 827610166.

It is an arithmetic number, because the mean of its divisors is an integer number (827610166).

Almost surely, 2^1655220331 is an apocalyptic number.

1655220331 is a deficient number, since it is larger than the sum of its proper divisors (1).

1655220331 is an equidigital number, since it uses as much as digits as its factorization.

1655220331 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5400, while the sum is 28.

The square root of 1655220331 is about 40684.3991107156. The cubic root of 1655220331 is about 1182.9106377780.

Adding to 1655220331 its reverse (1330225561), we get a palindrome (2985445892).

The spelling of 1655220331 in words is "one billion, six hundred fifty-five million, two hundred twenty thousand, three hundred thirty-one".