1971491 has 4 divisors (see below), whose sum is σ = 2057232. Its totient is φ = 1885752.

The previous prime is 1971481. The next prime is 1971503. The reversal of 1971491 is 1941791.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1971491 - 2⁶ = 1971427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1971401) 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, 42836 + ... + 42881.

It is an arithmetic number, because the mean of its divisors is an integer number (514308).

2^1971491 is an apocalyptic number.

1971491 is a deficient number, since it is larger than the sum of its proper divisors (85741).

1971491 is an equidigital number, since it uses as much as digits as its factorization.

1971491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85740.

The product of its digits is 2268, while the sum is 32.

The square root of 1971491 is about 1404.0979310575. The cubic root of 1971491 is about 125.3905862678.

The spelling of 1971491 in words is "one million, nine hundred seventy-one thousand, four hundred ninety-one".