1971952639 has 8 divisors (see below), whose sum is σ = 2089489280. Its totient is φ = 1855791000.

The previous prime is 1971952637. The next prime is 1971952667. The reversal of 1971952639 is 9362591791.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1971952639 - 2¹ = 1971952637 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1971952637) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 340797 + ... + 346534.

It is an arithmetic number, because the mean of its divisors is an integer number (261186160).

Almost surely, 2^1971952639 is an apocalyptic number.

1971952639 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

1971952639 is a deficient number, since it is larger than the sum of its proper divisors (117536641).

1971952639 is a wasteful number, since it uses less digits than its factorization.

1971952639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 687501.

The product of its digits is 918540, while the sum is 52.

The square root of 1971952639 is about 44406.6733611064. The cubic root of 1971952639 is about 1254.0037254412.

The spelling of 1971952639 in words is "one billion, nine hundred seventy-one million, nine hundred fifty-two thousand, six hundred thirty-nine".