1646426421 has 12 divisors (see below), whose sum is σ = 2518064172. Its totient is φ = 1033051776.

The previous prime is 1646426393. The next prime is 1646426423. The reversal of 1646426421 is 1246246461.

1646426421 is a `hidden beast` number, since 1 + 6 + 4 + 6 + 4 + 2 + 642 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1442936196 + 203490225 = 37986^2 + 14265^2 .

It is not a de Polignac number, because 1646426421 - 2⁵ = 1646426389 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1646426423) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5380326 + ... + 5380631.

It is an arithmetic number, because the mean of its divisors is an integer number (209838681).

Almost surely, 2^1646426421 is an apocalyptic number.

It is an amenable number.

1646426421 is a deficient number, since it is larger than the sum of its proper divisors (871637751).

1646426421 is a wasteful number, since it uses less digits than its factorization.

1646426421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10760980 (or 10760977 counting only the distinct ones).

The product of its digits is 55296, while the sum is 36.

The square root of 1646426421 is about 40576.1804634197. The cubic root of 1646426421 is about 1180.8120478100.

The spelling of 1646426421 in words is "one billion, six hundred forty-six million, four hundred twenty-six thousand, four hundred twenty-one".