154423721 has 2 divisors, whose sum is σ = 154423722. Its totient is φ = 154423720.

The previous prime is 154423673. The next prime is 154423727. The reversal of 154423721 is 127324451.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 150675625 + 3748096 = 12275^2 + 1936^2 .

It is an emirp because it is prime and its reverse (127324451) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-154423721 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (154423727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77211860 + 77211861.

It is an arithmetic number, because the mean of its divisors is an integer number (77211861).

Almost surely, 2^154423721 is an apocalyptic number.

It is an amenable number.

154423721 is a deficient number, since it is larger than the sum of its proper divisors (1).

154423721 is an equidigital number, since it uses as much as digits as its factorization.

154423721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6720, while the sum is 29.

The square root of 154423721 is about 12426.7341244592. The cubic root of 154423721 is about 536.5019905907.

The spelling of 154423721 in words is "one hundred fifty-four million, four hundred twenty-three thousand, seven hundred twenty-one".