1990278531 has 12 divisors (see below), whose sum is σ = 2883136152. Its totient is φ = 1323026496.

The previous prime is 1990278529. The next prime is 1990278541. The reversal of 1990278531 is 1358720991.

1990278531 is a `hidden beast` number, since 1 + 9 + 90 + 27 + 8 + 531 = 666.

1990278531 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 1990278531 - 2¹ = 1990278529 is a prime.

It is a super-2 number, since 2×1990278531² = 7922417261919035922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1990278541) 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, 315526 + ... + 321771.

It is an arithmetic number, because the mean of its divisors is an integer number (240261346).

Almost surely, 2^1990278531 is an apocalyptic number.

1990278531 is a deficient number, since it is larger than the sum of its proper divisors (892857621).

1990278531 is a wasteful number, since it uses less digits than its factorization.

1990278531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 637650 (or 637647 counting only the distinct ones).

The product of its (nonzero) digits is 136080, while the sum is 45.

The square root of 1990278531 is about 44612.5378229036. The cubic root of 1990278531 is about 1257.8763528263.

The spelling of 1990278531 in words is "one billion, nine hundred ninety million, two hundred seventy-eight thousand, five hundred thirty-one".