123154153981 has 2 divisors, whose sum is σ = 123154153982. Its totient is φ = 123154153980.

The previous prime is 123154153961. The next prime is 123154154021. The reversal of 123154153981 is 189351451321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 76126328100 + 47027825881 = 275910^2 + 216859^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-123154153981 is a prime.

It is a super-2 number, since 2×123154153981² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123154153961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61577076990 + 61577076991.

It is an arithmetic number, because the mean of its divisors is an integer number (61577076991).

Almost surely, 2^123154153981 is an apocalyptic number.

It is an amenable number.

123154153981 is a deficient number, since it is larger than the sum of its proper divisors (1).

123154153981 is an equidigital number, since it uses as much as digits as its factorization.

123154153981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 129600, while the sum is 43.

The spelling of 123154153981 in words is "one hundred twenty-three billion, one hundred fifty-four million, one hundred fifty-three thousand, nine hundred eighty-one".