1861908849 has 10 divisors (see below), whose sum is σ = 2781370130. Its totient is φ = 1241272512.

The previous prime is 1861908847. The next prime is 1861908859. The reversal of 1861908849 is 9488091681.

1861908849 is a `hidden beast` number, since 18 + 619 + 0 + 8 + 8 + 4 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1522170225 + 339738624 = 39015^2 + 18432^2 .

It is not a de Polignac number, because 1861908849 - 2¹ = 1861908847 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1861908795 and 1861908804.

It is not an unprimeable number, because it can be changed into a prime (1861908847) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 11493184 + ... + 11493345.

It is an arithmetic number, because the mean of its divisors is an integer number (278137013).

Almost surely, 2^1861908849 is an apocalyptic number.

It is an amenable number.

1861908849 is a deficient number, since it is larger than the sum of its proper divisors (919461281).

1861908849 is an equidigital number, since it uses as much as digits as its factorization.

1861908849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22986541 (or 22986532 counting only the distinct ones).

The product of its (nonzero) digits is 995328, while the sum is 54.

The square root of 1861908849 is about 43149.8418189453. The cubic root of 1861908849 is about 1230.2295050623.

The spelling of 1861908849 in words is "one billion, eight hundred sixty-one million, nine hundred eight thousand, eight hundred forty-nine".