1971661011257 has 8 divisors (see below), whose sum is σ = 2331027796800. Its totient is φ = 1631719457424.

The previous prime is 1971661011253. The next prime is 1971661011293. The reversal of 1971661011257 is 7521101661791.

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

It is not a de Polignac number, because 1971661011257 - 2² = 1971661011253 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1971661011253) 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, 4856307707 + ... + 4856308112.

It is an arithmetic number, because the mean of its divisors is an integer number (291378474600).

Almost surely, 2^{1971661011257} is an apocalyptic number.

It is an amenable number.

1971661011257 is a deficient number, since it is larger than the sum of its proper divisors (359366785543).

1971661011257 is an equidigital number, since it uses as much as digits as its factorization.

1971661011257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9712615855.

The product of its (nonzero) digits is 158760, while the sum is 47.

The spelling of 1971661011257 in words is "one trillion, nine hundred seventy-one billion, six hundred sixty-one million, eleven thousand, two hundred fifty-seven".