21451021452149 has 2 divisors, whose sum is σ = 21451021452150. Its totient is φ = 21451021452148.

The previous prime is 21451021452127. The next prime is 21451021452167. The reversal of 21451021452149 is 94125412015412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13316062177924 + 8134959274225 = 3649118^2 + 2852185^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21451021452149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21451021452169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10725510726074 + 10725510726075.

It is an arithmetic number, because the mean of its divisors is an integer number (10725510726075).

Almost surely, 2^{21451021452149} is an apocalyptic number.

It is an amenable number.

21451021452149 is a deficient number, since it is larger than the sum of its proper divisors (1).

21451021452149 is an equidigital number, since it uses as much as digits as its factorization.

21451021452149 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 115200, while the sum is 41.

The spelling of 21451021452149 in words is "twenty-one trillion, four hundred fifty-one billion, twenty-one million, four hundred fifty-two thousand, one hundred forty-nine".