154521421 has 2 divisors, whose sum is σ = 154521422. Its totient is φ = 154521420.

The previous prime is 154521407. The next prime is 154521439. The reversal of 154521421 is 124125451.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 132572196 + 21949225 = 11514^2 + 4685^2 .

It is an emirp because it is prime and its reverse (124125451) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 154521421 - 2¹¹ = 154519373 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (154521491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77260710 + 77260711.

It is an arithmetic number, because the mean of its divisors is an integer number (77260711).

Almost surely, 2^154521421 is an apocalyptic number.

It is an amenable number.

154521421 is a deficient number, since it is larger than the sum of its proper divisors (1).

154521421 is an equidigital number, since it uses as much as digits as its factorization.

154521421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1600, while the sum is 25.

The square root of 154521421 is about 12430.6645437804. The cubic root of 154521421 is about 536.6151105049.

Adding to 154521421 its reverse (124125451), we get a palindrome (278646872).

The spelling of 154521421 in words is "one hundred fifty-four million, five hundred twenty-one thousand, four hundred twenty-one".