1971531 has 6 divisors (see below), whose sum is σ = 2847780. Its totient is φ = 1314348.

The previous prime is 1971527. The next prime is 1971539. The reversal of 1971531 is 1351791.

It is a happy number.

It is not a de Polignac number, because 1971531 - 2² = 1971527 is a prime.

It is a super-2 number, since 2×1971531² = 7773868967922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1971495 and 1971504.

It is not an unprimeable number, because it can be changed into a prime (1971539) 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 5 ways as a sum of consecutive naturals, for example, 109521 + ... + 109538.

It is an arithmetic number, because the mean of its divisors is an integer number (474630).

2^1971531 is an apocalyptic number.

1971531 is a deficient number, since it is larger than the sum of its proper divisors (876249).

1971531 is a wasteful number, since it uses less digits than its factorization.

1971531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 219065 (or 219062 counting only the distinct ones).

The product of its digits is 945, while the sum is 27.

The square root of 1971531 is about 1404.1121750060. The cubic root of 1971531 is about 125.3914342874.

It can be divided in two parts, 197 and 1531, that added together give a cube (1728 = 12³).

The spelling of 1971531 in words is "one million, nine hundred seventy-one thousand, five hundred thirty-one".