1906638461 has 12 divisors (see below), whose sum is σ = 2388536892. Its totient is φ = 1508548608.

The previous prime is 1906638449. The next prime is 1906638469. The reversal of 1906638461 is 1648366091.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 103022500 + 1803615961 = 10150^2 + 42469^2 .

It is not a de Polignac number, because 1906638461 - 2²⁶ = 1839529597 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1906638469) 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, 1495940 + ... + 1497213.

It is an arithmetic number, because the mean of its divisors is an integer number (199044741).

Almost surely, 2^1906638461 is an apocalyptic number.

It is an amenable number.

1906638461 is a deficient number, since it is larger than the sum of its proper divisors (481898431).

1906638461 is a wasteful number, since it uses less digits than its factorization.

1906638461 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2993180 (or 2993173 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 44.

The square root of 1906638461 is about 43665.0714072472. The cubic root of 1906638461 is about 1240.0031349643.

The spelling of 1906638461 in words is "one billion, nine hundred six million, six hundred thirty-eight thousand, four hundred sixty-one".