1971538401 has 32 divisors (see below), whose sum is σ = 3165352960. Its totient is φ = 1066291776.

The previous prime is 1971538351. The next prime is 1971538409. The reversal of 1971538401 is 1048351791.

It is not a de Polignac number, because 1971538401 - 2¹⁴ = 1971522017 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1971538401.

It is not an unprimeable number, because it can be changed into a prime (1971538409) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 647655 + ... + 650691.

It is an arithmetic number, because the mean of its divisors is an integer number (98917280).

Almost surely, 2^1971538401 is an apocalyptic number.

It is an amenable number.

1971538401 is a deficient number, since it is larger than the sum of its proper divisors (1193814559).

1971538401 is a wasteful number, since it uses less digits than its factorization.

1971538401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4693.

The product of its (nonzero) digits is 30240, while the sum is 39.

The square root of 1971538401 is about 44402.0089748200. The cubic root of 1971538401 is about 1253.9159119102.

The spelling of 1971538401 in words is "one billion, nine hundred seventy-one million, five hundred thirty-eight thousand, four hundred one".