1990587887 has 2 divisors, whose sum is σ = 1990587888. Its totient is φ = 1990587886.

The previous prime is 1990587883. The next prime is 1990587899. The reversal of 1990587887 is 7887850991.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1990587887 - 2² = 1990587883 is a prime.

It is a super-2 number, since 2×1990587887² = 7924880271742249538, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1990587883) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 995293943 + 995293944.

It is an arithmetic number, because the mean of its divisors is an integer number (995293944).

Almost surely, 2^1990587887 is an apocalyptic number.

1990587887 is a deficient number, since it is larger than the sum of its proper divisors (1).

1990587887 is an equidigital number, since it uses as much as digits as its factorization.

1990587887 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10160640, while the sum is 62.

The square root of 1990587887 is about 44616.0048301055. The cubic root of 1990587887 is about 1257.9415215002.

The spelling of 1990587887 in words is "one billion, nine hundred ninety million, five hundred eighty-seven thousand, eight hundred eighty-seven".