151861 has 4 divisors (see below), whose sum is σ = 160812. Its totient is φ = 142912.

The previous prime is 151849. The next prime is 151871. The reversal of 151861 is 168151.

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 78961 + 72900 = 281^2 + 270^2 .

It is a cyclic number.

It is not a de Polignac number, because 151861 - 2⁷ = 151733 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (151841) 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, 4450 + ... + 4483.

It is an arithmetic number, because the mean of its divisors is an integer number (40203).

2¹⁵¹⁸⁶¹ is an apocalyptic number.

It is an amenable number.

151861 is a deficient number, since it is larger than the sum of its proper divisors (8951).

151861 is an equidigital number, since it uses as much as digits as its factorization.

151861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8950.

The product of its digits is 240, while the sum is 22.

The square root of 151861 is about 389.6934692807. The cubic root of 151861 is about 53.3517601258.

Subtracting 151861 from its reverse (168151), we obtain a triangular number (16290 = T₁₈₀).

The spelling of 151861 in words is "one hundred fifty-one thousand, eight hundred sixty-one".