151997 has 4 divisors (see below), whose sum is σ = 160956. Its totient is φ = 143040.

The previous prime is 151969. The next prime is 152003. The reversal of 151997 is 799151.

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 109561 + 42436 = 331^2 + 206^2 .

It is a cyclic number.

It is not a de Polignac number, because 151997 - 2¹⁴ = 135613 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (151937) 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, 4454 + ... + 4487.

It is an arithmetic number, because the mean of its divisors is an integer number (40239).

2¹⁵¹⁹⁹⁷ is an apocalyptic number.

151997 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

151997 is a deficient number, since it is larger than the sum of its proper divisors (8959).

151997 is an equidigital number, since it uses as much as digits as its factorization.

151997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8958.

The product of its digits is 2835, while the sum is 32.

The square root of 151997 is about 389.8679263546. The cubic root of 151997 is about 53.3676818666.

The spelling of 151997 in words is "one hundred fifty-one thousand, nine hundred ninety-seven".