20154433991 has 2 divisors, whose sum is σ = 20154433992. Its totient is φ = 20154433990.

The previous prime is 20154433973. The next prime is 20154434039. The reversal of 20154433991 is 19933445102.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20154433991 - 2⁶ = 20154433927 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20154433291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10077216995 + 10077216996.

It is an arithmetic number, because the mean of its divisors is an integer number (10077216996).

Almost surely, 2^20154433991 is an apocalyptic number.

20154433991 is a deficient number, since it is larger than the sum of its proper divisors (1).

20154433991 is an equidigital number, since it uses as much as digits as its factorization.

20154433991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 116640, while the sum is 41.

The spelling of 20154433991 in words is "twenty billion, one hundred fifty-four million, four hundred thirty-three thousand, nine hundred ninety-one".