154404042551021 has 2 divisors, whose sum is σ = 154404042551022. Its totient is φ = 154404042551020.

The previous prime is 154404042551009. The next prime is 154404042551039. The reversal of 154404042551021 is 120155240404451.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 137684080660996 + 16719961890025 = 11733886^2 + 4089005^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-154404042551021 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (154404072551021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77202021275510 + 77202021275511.

It is an arithmetic number, because the mean of its divisors is an integer number (77202021275511).

Almost surely, 2^{154404042551021} is an apocalyptic number.

It is an amenable number.

154404042551021 is a deficient number, since it is larger than the sum of its proper divisors (1).

154404042551021 is an equidigital number, since it uses as much as digits as its factorization.

154404042551021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 128000, while the sum is 38.

Adding to 154404042551021 its reverse (120155240404451), we get a palindrome (274559282955472).

The spelling of 154404042551021 in words is "one hundred fifty-four trillion, four hundred four billion, forty-two million, five hundred fifty-one thousand, twenty-one".