1995903021 has 12 divisors (see below), whose sum is σ = 3041688032. Its totient is φ = 1140399024.

The previous prime is 1995903011. The next prime is 1995903023. The reversal of 1995903021 is 1203095991.

It is not a de Polignac number, because 1995903021 - 2¹⁷ = 1995771949 is a prime.

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1995903023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 199855 + ... + 209603.

Almost surely, 2^1995903021 is an apocalyptic number.

It is an amenable number.

1995903021 is a deficient number, since it is larger than the sum of its proper divisors (1045785011).

1995903021 is an frugal number, since it uses more digits than its factorization.

1995903021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19508 (or 9759 counting only the distinct ones).

The product of its (nonzero) digits is 21870, while the sum is 39.

The square root of 1995903021 is about 44675.5304501245. The cubic root of 1995903021 is about 1259.0601500984.

The spelling of 1995903021 in words is "one billion, nine hundred ninety-five million, nine hundred three thousand, twenty-one".