906721820 has 12 divisors (see below), whose sum is σ = 1904115864. Its totient is φ = 362688720.

The previous prime is 906721807. The next prime is 906721903. The reversal of 906721820 is 28127609.

It is a happy number.

906721820 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×906721820² = 1644288917728224800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22668026 + ... + 22668065.

It is an arithmetic number, because the mean of its divisors is an integer number (158676322).

Almost surely, 2^906721820 is an apocalyptic number.

It is an amenable number.

906721820 is an abundant number, since it is smaller than the sum of its proper divisors (997394044).

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

906721820 is a wasteful number, since it uses less digits than its factorization.

906721820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45336100 (or 45336098 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 906721820 is about 30111.8219309294. The cubic root of 906721820 is about 967.8870718955.

The spelling of 906721820 in words is "nine hundred six million, seven hundred twenty-one thousand, eight hundred twenty".