20154220091 has 2 divisors, whose sum is σ = 20154220092. Its totient is φ = 20154220090.

The previous prime is 20154220057. The next prime is 20154220127. The reversal of 20154220091 is 19002245102.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20154220091 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20154220091.

It is not a weakly prime, because it can be changed into another prime (20154223091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10077110045 + 10077110046.

It is an arithmetic number, because the mean of its divisors is an integer number (10077110046).

Almost surely, 2^20154220091 is an apocalyptic number.

20154220091 is a deficient number, since it is larger than the sum of its proper divisors (1).

20154220091 is an equidigital number, since it uses as much as digits as its factorization.

20154220091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1440, while the sum is 26.

Adding to 20154220091 its reverse (19002245102), we get a palindrome (39156465193).

The spelling of 20154220091 in words is "twenty billion, one hundred fifty-four million, two hundred twenty thousand, ninety-one".