2655220991 has 4 divisors (see below), whose sum is σ = 2656596552. Its totient is φ = 2653845432.

The previous prime is 2655220957. The next prime is 2655220999. The reversal of 2655220991 is 1990225562.

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-2655220991 is a prime.

It is a super-2 number, since 2×2655220991² = 14100397022094044162, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2655220999) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 684881 + ... + 688746.

It is an arithmetic number, because the mean of its divisors is an integer number (664149138).

Almost surely, 2^2655220991 is an apocalyptic number.

2655220991 is a deficient number, since it is larger than the sum of its proper divisors (1375561).

2655220991 is a wasteful number, since it uses less digits than its factorization.

2655220991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1375560.

The product of its (nonzero) digits is 97200, while the sum is 41.

The square root of 2655220991 is about 51528.8364995757. The cubic root of 2655220991 is about 1384.7357063235.

The spelling of 2655220991 in words is "two billion, six hundred fifty-five million, two hundred twenty thousand, nine hundred ninety-one".