291270987861 has 16 divisors (see below), whose sum is σ = 444347624064. Its totient is φ = 166250769984.

The previous prime is 291270987853. The next prime is 291270987869. The reversal of 291270987861 is 168789072192.

It is an interprime number because it is at equal distance from previous prime (291270987853) and next prime (291270987869).

It is not a de Polignac number, because 291270987861 - 2³ = 291270987853 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 291270987795 and 291270987804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (291270987869) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7889250 + ... + 7926083.

It is an arithmetic number, because the mean of its divisors is an integer number (27771726504).

Almost surely, 2^291270987861 is an apocalyptic number.

291270987861 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

291270987861 is a deficient number, since it is larger than the sum of its proper divisors (153076636203).

291270987861 is a wasteful number, since it uses less digits than its factorization.

291270987861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15816220.

The product of its (nonzero) digits is 6096384, while the sum is 60.

The spelling of 291270987861 in words is "two hundred ninety-one billion, two hundred seventy million, nine hundred eighty-seven thousand, eight hundred sixty-one".