921946547391 has 16 divisors (see below), whose sum is σ = 1241111359488. Its totient is φ = 608723337600.

The previous prime is 921946547387. The next prime is 921946547413. The reversal of 921946547391 is 193745649129.

It is not a de Polignac number, because 921946547391 - 2² = 921946547387 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (921946547311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1901370 + ... + 2336471.

It is an arithmetic number, because the mean of its divisors is an integer number (77569459968).

Almost surely, 2^921946547391 is an apocalyptic number.

921946547391 is a deficient number, since it is larger than the sum of its proper divisors (319164812097).

921946547391 is a wasteful number, since it uses less digits than its factorization.

921946547391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4238542.

The product of its digits is 14696640, while the sum is 60.

The spelling of 921946547391 in words is "nine hundred twenty-one billion, nine hundred forty-six million, five hundred forty-seven thousand, three hundred ninety-one".