154561681 has 4 divisors (see below), whose sum is σ = 155149632. Its totient is φ = 153973732.

The previous prime is 154561663. The next prime is 154561699. The reversal of 154561681 is 186165451.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (154561663) and next prime (154561699).

It is a cyclic number.

It is not a de Polignac number, because 154561681 - 2⁷ = 154561553 is a prime.

It is a super-2 number, since 2×154561681² = 47778626467091522, 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 154561681.

It is not an unprimeable number, because it can be changed into a prime (154561601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 293581 + ... + 294106.

It is an arithmetic number, because the mean of its divisors is an integer number (38787408).

Almost surely, 2^154561681 is an apocalyptic number.

It is an amenable number.

154561681 is a deficient number, since it is larger than the sum of its proper divisors (587951).

154561681 is an equidigital number, since it uses as much as digits as its factorization.

154561681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 587950.

The product of its digits is 28800, while the sum is 37.

The square root of 154561681 is about 12432.2838207628. The cubic root of 154561681 is about 536.6617108364.

The spelling of 154561681 in words is "one hundred fifty-four million, five hundred sixty-one thousand, six hundred eighty-one".