1287640290 has 16 divisors (see below), whose sum is σ = 3090336768. Its totient is φ = 343370736.

The previous prime is 1287640271. The next prime is 1287640327. The reversal of 1287640290 is 920467821.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21460642 + ... + 21460701.

It is an arithmetic number, because the mean of its divisors is an integer number (193146048).

Almost surely, 2^1287640290 is an apocalyptic number.

1287640290 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1287640290 is an abundant number, since it is smaller than the sum of its proper divisors (1802696478).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1287640290 is a wasteful number, since it uses less digits than its factorization.

1287640290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42921353.

The product of its (nonzero) digits is 48384, while the sum is 39.

The square root of 1287640290 is about 35883.7050762599. The cubic root of 1287640290 is about 1087.9230685809.

The spelling of 1287640290 in words is "one billion, two hundred eighty-seven million, six hundred forty thousand, two hundred ninety".