971551 has 4 divisors (see below), whose sum is σ = 1110352. Its totient is φ = 832752.

The previous prime is 971549. The next prime is 971561. The reversal of 971551 is 155179.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 155179 = 29 ⋅5351.

It is a cyclic number.

It is not a de Polignac number, because 971551 - 2¹ = 971549 is a prime.

It is a super-2 number, since 2×971551² = 1887822691202, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (971501) 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, 69390 + ... + 69403.

It is an arithmetic number, because the mean of its divisors is an integer number (277588).

2⁹⁷¹⁵⁵¹ is an apocalyptic number.

971551 is a deficient number, since it is larger than the sum of its proper divisors (138801).

971551 is a wasteful number, since it uses less digits than its factorization.

971551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138800.

The product of its digits is 1575, while the sum is 28.

The square root of 971551 is about 985.6728666246. The cubic root of 971551 is about 99.0425623879.

The spelling of 971551 in words is "nine hundred seventy-one thousand, five hundred fifty-one".