154261981 has 4 divisors (see below), whose sum is σ = 154331100. Its totient is φ = 154192864.

The previous prime is 154261963. The next prime is 154261993. The reversal of 154261981 is 189162451.

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

It can be written as a sum of positive squares in 2 ways, for example, as 63059481 + 91202500 = 7941^2 + 9550^2 .

It is a cyclic number.

It is not a de Polignac number, because 154261981 - 2⁵ = 154261949 is a prime.

It is a super-2 number, since 2×154261981² = 47593517564088722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 154261981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (154261901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31096 + ... + 35713.

It is an arithmetic number, because the mean of its divisors is an integer number (38582775).

Almost surely, 2^154261981 is an apocalyptic number.

It is an amenable number.

154261981 is a deficient number, since it is larger than the sum of its proper divisors (69119).

154261981 is an equidigital number, since it uses as much as digits as its factorization.

154261981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69118.

The product of its digits is 17280, while the sum is 37.

The square root of 154261981 is about 12420.2246759066. The cubic root of 154261981 is about 536.3146183743.

The spelling of 154261981 in words is "one hundred fifty-four million, two hundred sixty-one thousand, nine hundred eighty-one".