921861864761 has 4 divisors (see below), whose sum is σ = 921871137024. Its totient is φ = 921852592500.

The previous prime is 921861864751. The next prime is 921861864787. The reversal of 921861864761 is 167468168129.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 167468168129 = 433 ⋅386762513.

It is a cyclic number.

It is not a de Polignac number, because 921861864761 - 2³⁰ = 920788122937 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 921861864761.

It is not an unprimeable number, because it can be changed into a prime (921861864751) 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, 4485365 + ... + 4686386.

It is an arithmetic number, because the mean of its divisors is an integer number (230467784256).

Almost surely, 2^921861864761 is an apocalyptic number.

It is an amenable number.

921861864761 is a deficient number, since it is larger than the sum of its proper divisors (9272263).

921861864761 is a wasteful number, since it uses less digits than its factorization.

921861864761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9272262.

The product of its digits is 6967296, while the sum is 59.

The spelling of 921861864761 in words is "nine hundred twenty-one billion, eight hundred sixty-one million, eight hundred sixty-four thousand, seven hundred sixty-one".