2155446666421 has 4 divisors (see below), whose sum is σ = 2156911961344. Its totient is φ = 2153981371500.

The previous prime is 2155446666413. The next prime is 2155446666427. The reversal of 2155446666421 is 1246666445512.

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.

It is a cyclic number.

It is not a de Polignac number, because 2155446666421 - 2³ = 2155446666413 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2155446666427) 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, 732645255 + ... + 732648196.

It is an arithmetic number, because the mean of its divisors is an integer number (539227990336).

Almost surely, 2^{2155446666421} is an apocalyptic number.

It is an amenable number.

2155446666421 is a deficient number, since it is larger than the sum of its proper divisors (1465294923).

2155446666421 is a wasteful number, since it uses less digits than its factorization.

2155446666421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1465294922.

The product of its digits is 8294400, while the sum is 52.

The spelling of 2155446666421 in words is "two trillion, one hundred fifty-five billion, four hundred forty-six million, six hundred sixty-six thousand, four hundred twenty-one".