154681645138 has 4 divisors (see below), whose sum is σ = 232022467710. Its totient is φ = 77340822568.

The previous prime is 154681645133. The next prime is 154681645163. The reversal of 154681645138 is 831546186451.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 152980330129 + 1701315009 = 391127^2 + 41247^2 .

It is a super-2 number, since 2×154681645138² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (154681645133) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38670411283 + ... + 38670411286.

Almost surely, 2^154681645138 is an apocalyptic number.

154681645138 is a deficient number, since it is larger than the sum of its proper divisors (77340822572).

154681645138 is an equidigital number, since it uses as much as digits as its factorization.

154681645138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77340822571.

The product of its digits is 2764800, while the sum is 52.

The spelling of 154681645138 in words is "one hundred fifty-four billion, six hundred eighty-one million, six hundred forty-five thousand, one hundred thirty-eight".