21171161340154 has 12 divisors (see below), whose sum is σ = 36941516216154. Its totient is φ = 9073354860024.

The previous prime is 21171161340143. The next prime is 21171161340167. The reversal of 21171161340154 is 45104316117112.

It can be written as a sum of positive squares in only one way, i.e., 18283449087225 + 2887712252929 = 4275915^2 + 1699327^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 108016129189 + ... + 108016129384.

Almost surely, 2^{21171161340154} is an apocalyptic number.

21171161340154 is a deficient number, since it is larger than the sum of its proper divisors (15770354876000).

21171161340154 is a wasteful number, since it uses less digits than its factorization.

21171161340154 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216032258589 (or 216032258582 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 37.

Adding to 21171161340154 its reverse (45104316117112), we get a palindrome (66275477457266).

The spelling of 21171161340154 in words is "twenty-one trillion, one hundred seventy-one billion, one hundred sixty-one million, three hundred forty thousand, one hundred fifty-four".