21548142061 has 2 divisors, whose sum is σ = 21548142062. Its totient is φ = 21548142060.

The previous prime is 21548142059. The next prime is 21548142113. The reversal of 21548142061 is 16024184512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14739416836 + 6808725225 = 121406^2 + 82515^2 .

It is a cyclic number.

It is not a de Polignac number, because 21548142061 - 2¹ = 21548142059 is a prime.

Together with 21548142059, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21548142361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10774071030 + 10774071031.

It is an arithmetic number, because the mean of its divisors is an integer number (10774071031).

Almost surely, 2^21548142061 is an apocalyptic number.

It is an amenable number.

21548142061 is a deficient number, since it is larger than the sum of its proper divisors (1).

21548142061 is an equidigital number, since it uses as much as digits as its factorization.

21548142061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15360, while the sum is 34.

The spelling of 21548142061 in words is "twenty-one billion, five hundred forty-eight million, one hundred forty-two thousand, sixty-one".