151111561 has 4 divisors (see below), whose sum is σ = 151171092. Its totient is φ = 151052032.

The previous prime is 151111549. The next prime is 151111601. The reversal of 151111561 is 165111151.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 165111151 = 727 ⋅227113.

It can be written as a sum of positive squares in 2 ways, for example, as 46172025 + 104939536 = 6795^2 + 10244^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-151111561 is a prime.

It is a super-3 number, since 3×151111561³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (151111531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25780 + ... + 31093.

It is an arithmetic number, because the mean of its divisors is an integer number (37792773).

Almost surely, 2^151111561 is an apocalyptic number.

It is an amenable number.

151111561 is a deficient number, since it is larger than the sum of its proper divisors (59531).

151111561 is an equidigital number, since it uses as much as digits as its factorization.

151111561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59530.

The product of its digits is 150, while the sum is 22.

The square root of 151111561 is about 12292.7442420316. The cubic root of 151111561 is about 532.6385112874.

The spelling of 151111561 in words is "one hundred fifty-one million, one hundred eleven thousand, five hundred sixty-one".