1861441815 has 16 divisors (see below), whose sum is σ = 3041676288. Its totient is φ = 971645856.

The previous prime is 1861441811. The next prime is 1861441823. The reversal of 1861441815 is 5181441681.

It is not a de Polignac number, because 1861441815 - 2² = 1861441811 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1861441811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1319467 + ... + 1320876.

It is an arithmetic number, because the mean of its divisors is an integer number (190104768).

Almost surely, 2^1861441815 is an apocalyptic number.

1861441815 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1861441815 is a deficient number, since it is larger than the sum of its proper divisors (1180234473).

1861441815 is a wasteful number, since it uses less digits than its factorization.

1861441815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2640398.

The product of its digits is 30720, while the sum is 39.

The square root of 1861441815 is about 43144.4297099869. The cubic root of 1861441815 is about 1230.1266344601.

The spelling of 1861441815 in words is "one billion, eight hundred sixty-one million, four hundred forty-one thousand, eight hundred fifteen".