821900007 has 16 divisors (see below), whose sum is σ = 1222956000. Its totient is φ = 545536512.

The previous prime is 821899987. The next prime is 821900011. The reversal of 821900007 is 700009128.

It is not a de Polignac number, because 821900007 - 2⁷ = 821899879 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821900077) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 60282 + ... + 72647.

It is an arithmetic number, because the mean of its divisors is an integer number (76434750).

Almost surely, 2^821900007 is an apocalyptic number.

821900007 is a deficient number, since it is larger than the sum of its proper divisors (401055993).

821900007 is a wasteful number, since it uses less digits than its factorization.

821900007 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133167 (or 133161 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The square root of 821900007 is about 28668.7984924377. The cubic root of 821900007 is about 936.7125265698.

The spelling of 821900007 in words is "eight hundred twenty-one million, nine hundred thousand, seven".