154549721 has 2 divisors, whose sum is σ = 154549722. Its totient is φ = 154549720.

The previous prime is 154549711. The next prime is 154549727. The reversal of 154549721 is 127945451.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 108160000 + 46389721 = 10400^2 + 6811^2 .

It is a cyclic number.

It is not a de Polignac number, because 154549721 - 2¹⁰ = 154548697 is a prime.

It is a super-2 number, since 2×154549721² = 47771232522355682, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (154549727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77274860 + 77274861.

It is an arithmetic number, because the mean of its divisors is an integer number (77274861).

Almost surely, 2^154549721 is an apocalyptic number.

It is an amenable number.

154549721 is a deficient number, since it is larger than the sum of its proper divisors (1).

154549721 is an equidigital number, since it uses as much as digits as its factorization.

154549721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 50400, while the sum is 38.

The square root of 154549721 is about 12431.8028057076. The cubic root of 154549721 is about 536.6478681652.

The spelling of 154549721 in words is "one hundred fifty-four million, five hundred forty-nine thousand, seven hundred twenty-one".