1891378290 has 16 divisors (see below), whose sum is σ = 4539307968. Its totient is φ = 504367536.

The previous prime is 1891378283. The next prime is 1891378319. The reversal of 1891378290 is 928731981.

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, 31522942 + ... + 31523001.

It is an arithmetic number, because the mean of its divisors is an integer number (283706748).

Almost surely, 2^1891378290 is an apocalyptic number.

1891378290 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1891378290 is an abundant number, since it is smaller than the sum of its proper divisors (2647929678).

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

1891378290 is a wasteful number, since it uses less digits than its factorization.

1891378290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63045953.

The product of its (nonzero) digits is 217728, while the sum is 48.

The square root of 1891378290 is about 43489.9791906136. The cubic root of 1891378290 is about 1236.6860632799.

The spelling of 1891378290 in words is "one billion, eight hundred ninety-one million, three hundred seventy-eight thousand, two hundred ninety".