21489019157 has 2 divisors, whose sum is σ = 21489019158. Its totient is φ = 21489019156.

The previous prime is 21489019127. The next prime is 21489019213. The reversal of 21489019157 is 75191098412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18789281476 + 2699737681 = 137074^2 + 51959^2 .

It is a cyclic number.

It is not a de Polignac number, because 21489019157 - 2²² = 21484824853 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21489019127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10744509578 + 10744509579.

It is an arithmetic number, because the mean of its divisors is an integer number (10744509579).

Almost surely, 2^21489019157 is an apocalyptic number.

It is an amenable number.

21489019157 is a deficient number, since it is larger than the sum of its proper divisors (1).

21489019157 is an equidigital number, since it uses as much as digits as its factorization.

21489019157 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 181440, while the sum is 47.

The spelling of 21489019157 in words is "twenty-one billion, four hundred eighty-nine million, nineteen thousand, one hundred fifty-seven".