5620921991 has 2 divisors, whose sum is σ = 5620921992. Its totient is φ = 5620921990.

The previous prime is 5620921979. The next prime is 5620921997. The reversal of 5620921991 is 1991290265.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-5620921991 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (5620921997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2810460995 + 2810460996.

It is an arithmetic number, because the mean of its divisors is an integer number (2810460996).

Almost surely, 2^5620921991 is an apocalyptic number.

5620921991 is a deficient number, since it is larger than the sum of its proper divisors (1).

5620921991 is an equidigital number, since it uses as much as digits as its factorization.

5620921991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 87480, while the sum is 44.

The square root of 5620921991 is about 74972.8083440923. The cubic root of 5620921991 is about 1778.0167692937.

The spelling of 5620921991 in words is "five billion, six hundred twenty million, nine hundred twenty-one thousand, nine hundred ninety-one".