1861420815 has 12 divisors (see below), whose sum is σ = 3226462824. Its totient is φ = 992757744.

The previous prime is 1861420807. The next prime is 1861420817. The reversal of 1861420815 is 5180241681.

1861420815 is a `hidden beast` number, since 1 + 8 + 614 + 20 + 8 + 15 = 666.

It is not a de Polignac number, because 1861420815 - 2³ = 1861420807 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1861420815.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1861420817) 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, 20682409 + ... + 20682498.

It is an arithmetic number, because the mean of its divisors is an integer number (268871902).

Almost surely, 2^1861420815 is an apocalyptic number.

1861420815 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1861420815 is a deficient number, since it is larger than the sum of its proper divisors (1365042009).

1861420815 is a wasteful number, since it uses less digits than its factorization.

1861420815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41364918 (or 41364915 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 36.

The square root of 1861420815 is about 43144.1863406879. The cubic root of 1861420815 is about 1230.1220085197.

The spelling of 1861420815 in words is "one billion, eight hundred sixty-one million, four hundred twenty thousand, eight hundred fifteen".