1921157810 has 32 divisors (see below), whose sum is σ = 4062647232. Its totient is φ = 644863680.

The previous prime is 1921157807. The next prime is 1921157857. The reversal of 1921157810 is 187511291.

It is a super-2 number, since 2×1921157810² = 7381694661847992200, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 670304 + ... + 673163.

It is an arithmetic number, because the mean of its divisors is an integer number (126957726).

Almost surely, 2^1921157810 is an apocalyptic number.

1921157810 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1921157810 is an abundant number, since it is smaller than the sum of its proper divisors (2141489422).

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

1921157810 is a wasteful number, since it uses less digits than its factorization.

1921157810 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1343498.

The product of its (nonzero) digits is 5040, while the sum is 35.

The square root of 1921157810 is about 43831.0142479044. The cubic root of 1921157810 is about 1243.1427844624.

The spelling of 1921157810 in words is "one billion, nine hundred twenty-one million, one hundred fifty-seven thousand, eight hundred ten".