821150640 has 60 divisors (see below), whose sum is σ = 2757699984. Its totient is φ = 218973312.

The previous prime is 821150633. The next prime is 821150641. The reversal of 821150640 is 46051128.

821150640 is a `hidden beast` number, since 8 + 2 + 1 + 15 + 0 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (60).

It is not an unprimeable number, because it can be changed into a prime (821150641) 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, 569524 + ... + 570963.

Almost surely, 2^821150640 is an apocalyptic number.

821150640 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

821150640 is an abundant number, since it is smaller than the sum of its proper divisors (1936549344).

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

821150640 is a wasteful number, since it uses less digits than its factorization.

821150640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1140506 (or 1140497 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 821150640 is about 28655.7261293446. The cubic root of 821150640 is about 936.4277575835.

The spelling of 821150640 in words is "eight hundred twenty-one million, one hundred fifty thousand, six hundred forty".