1966292221 has 4 divisors (see below), whose sum is σ = 2019435292. Its totient is φ = 1913149152.

The previous prime is 1966292177. The next prime is 1966292231. The reversal of 1966292221 is 1222926691.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1222926691 = 7 ⋅174703813.

It can be written as a sum of positive squares in 2 ways, for example, as 1413384025 + 552908196 = 37595^2 + 23514^2 .

It is a cyclic number.

It is not a de Polignac number, because 1966292221 - 2⁹ = 1966291709 is a prime.

It is a super-2 number, since 2×1966292221² = 7732610196730225682, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1966292231) 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, 26571480 + ... + 26571553.

It is an arithmetic number, because the mean of its divisors is an integer number (504858823).

Almost surely, 2^1966292221 is an apocalyptic number.

It is an amenable number.

1966292221 is a deficient number, since it is larger than the sum of its proper divisors (53143071).

1966292221 is an equidigital number, since it uses as much as digits as its factorization.

1966292221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53143070.

The product of its digits is 46656, while the sum is 40.

The square root of 1966292221 is about 44342.8936922254. The cubic root of 1966292221 is about 1252.8027182662.

The spelling of 1966292221 in words is "one billion, nine hundred sixty-six million, two hundred ninety-two thousand, two hundred twenty-one".