5655021991 has 2 divisors, whose sum is σ = 5655021992. Its totient is φ = 5655021990.

The previous prime is 5655021979. The next prime is 5655022013. The reversal of 5655021991 is 1991205565.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 5655021991 - 2⁵ = 5655021959 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (5653021991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2827510995 + 2827510996.

It is an arithmetic number, because the mean of its divisors is an integer number (2827510996).

Almost surely, 2^5655021991 is an apocalyptic number.

5655021991 is a deficient number, since it is larger than the sum of its proper divisors (1).

5655021991 is an equidigital number, since it uses as much as digits as its factorization.

5655021991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 121500, while the sum is 43.

The square root of 5655021991 is about 75199.8802592132. The cubic root of 5655021991 is about 1781.6050404199.

The spelling of 5655021991 in words is "five billion, six hundred fifty-five million, twenty-one thousand, nine hundred ninety-one".