821981090 has 32 divisors (see below), whose sum is σ = 1697549184. Its totient is φ = 280719360.

The previous prime is 821981071. The next prime is 821981101. The reversal of 821981090 is 90189128.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4856 + ... + 40835.

It is an arithmetic number, because the mean of its divisors is an integer number (53048412).

Almost surely, 2^821981090 is an apocalyptic number.

821981090 is an abundant number, since it is smaller than the sum of its proper divisors (875568094).

821981090 is a wasteful number, since it uses less digits than its factorization.

821981090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45962.

The product of its (nonzero) digits is 10368, while the sum is 38.

The square root of 821981090 is about 28670.2125907709. The cubic root of 821981090 is about 936.7433287614.

The spelling of 821981090 in words is "eight hundred twenty-one million, nine hundred eighty-one thousand, ninety".