1865425221 has 24 divisors (see below), whose sum is σ = 3048331104. Its totient is φ = 1130559120.

The previous prime is 1865425213. The next prime is 1865425229. The reversal of 1865425221 is 1225245681.

1865425221 is a `hidden beast` number, since 1 + 8 + 6 + 5 + 425 + 221 = 666.

It is an interprime number because it is at equal distance from previous prime (1865425213) and next prime (1865425229).

It is not a de Polignac number, because 1865425221 - 2³ = 1865425213 is a prime.

It is a super-2 number, since 2×1865425221² = 6959622510285797682, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1865425229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 346266 + ... + 351611.

It is an arithmetic number, because the mean of its divisors is an integer number (127013796).

Almost surely, 2^1865425221 is an apocalyptic number.

1865425221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1865425221 is a deficient number, since it is larger than the sum of its proper divisors (1182905883).

1865425221 is an equidigital number, since it uses as much as digits as its factorization.

1865425221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 697903 (or 697891 counting only the distinct ones).

The product of its digits is 38400, while the sum is 36.

The square root of 1865425221 is about 43190.5686579837. The cubic root of 1865425221 is about 1231.0034821087.

The spelling of 1865425221 in words is "one billion, eight hundred sixty-five million, four hundred twenty-five thousand, two hundred twenty-one".