138866473 has 2 divisors, whose sum is σ = 138866474. Its totient is φ = 138866472.

The previous prime is 138866449. The next prime is 138866477. The reversal of 138866473 is 374668831.

138866473 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 123476544 + 15389929 = 11112^2 + 3923^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138866473 is a prime.

It is not a weakly prime, because it can be changed into another prime (138866477) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69433236 + 69433237.

It is an arithmetic number, because the mean of its divisors is an integer number (69433237).

Almost surely, 2^138866473 is an apocalyptic number.

It is an amenable number.

138866473 is a deficient number, since it is larger than the sum of its proper divisors (1).

138866473 is an equidigital number, since it uses as much as digits as its factorization.

138866473 is an evil number, because the sum of its binary digits is even.

The product of its digits is 580608, while the sum is 46.

The square root of 138866473 is about 11784.1619557778. The cubic root of 138866473 is about 517.8442222752.

The spelling of 138866473 in words is "one hundred thirty-eight million, eight hundred sixty-six thousand, four hundred seventy-three".