20070991 has 2 divisors, whose sum is σ = 20070992. Its totient is φ = 20070990.

The previous prime is 20070979. The next prime is 20070997. The reversal of 20070991 is 19907002.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20070991 - 2¹³ = 20062799 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20070997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10035495 + 10035496.

It is an arithmetic number, because the mean of its divisors is an integer number (10035496).

Almost surely, 2^20070991 is an apocalyptic number.

20070991 is a deficient number, since it is larger than the sum of its proper divisors (1).

20070991 is an equidigital number, since it uses as much as digits as its factorization.

20070991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1134, while the sum is 28.

The square root of 20070991 is about 4480.0659593359. The cubic root of 20070991 is about 271.7625477779.

Adding to 20070991 its reverse (19907002), we get a palindrome (39977993).

The spelling of 20070991 in words is "twenty million, seventy thousand, nine hundred ninety-one".