1971140187 has 4 divisors (see below), whose sum is σ = 2628186920. Its totient is φ = 1314093456.

The previous prime is 1971140147. The next prime is 1971140207. The reversal of 1971140187 is 7810411791.

It is a happy number.

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

It is not a de Polignac number, because 1971140187 - 2⁸ = 1971139931 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1971140147) 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, 328523362 + ... + 328523367.

It is an arithmetic number, because the mean of its divisors is an integer number (657046730).

Almost surely, 2^1971140187 is an apocalyptic number.

1971140187 is a deficient number, since it is larger than the sum of its proper divisors (657046733).

1971140187 is an equidigital number, since it uses as much as digits as its factorization.

1971140187 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 657046732.

The product of its (nonzero) digits is 14112, while the sum is 39.

The square root of 1971140187 is about 44397.5245593716. The cubic root of 1971140187 is about 1253.8314836802.

The spelling of 1971140187 in words is "one billion, nine hundred seventy-one million, one hundred forty thousand, one hundred eighty-seven".