1861950109 has 4 divisors (see below), whose sum is σ = 1971476604. Its totient is φ = 1752423616.

The previous prime is 1861950091. The next prime is 1861950127. The reversal of 1861950109 is 9010591681.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (1861950091) and next prime (1861950127).

It can be written as a sum of positive squares in 2 ways, for example, as 1501330009 + 360620100 = 38747^2 + 18990^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1861950109 is a prime.

It is a super-2 number, since 2×1861950109² = 6933716416810223762, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1861957109) 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, 54763222 + ... + 54763255.

It is an arithmetic number, because the mean of its divisors is an integer number (492869151).

Almost surely, 2^1861950109 is an apocalyptic number.

It is an amenable number.

1861950109 is a deficient number, since it is larger than the sum of its proper divisors (109526495).

1861950109 is a wasteful number, since it uses less digits than its factorization.

1861950109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109526494.

The product of its (nonzero) digits is 19440, while the sum is 40.

The square root of 1861950109 is about 43150.3199177017. The cubic root of 1861950109 is about 1230.2385923124.

The spelling of 1861950109 in words is "one billion, eight hundred sixty-one million, nine hundred fifty thousand, one hundred nine".