1056821720 has 16 divisors (see below), whose sum is σ = 2377848960. Its totient is φ = 422728672.

The previous prime is 1056821719. The next prime is 1056821761. The reversal of 1056821720 is 271286501.

It is a super-2 number, since 2×1056821720² = 2233744295727516800, 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, 13210232 + ... + 13210311.

It is an arithmetic number, because the mean of its divisors is an integer number (148615560).

Almost surely, 2^1056821720 is an apocalyptic number.

1056821720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1056821720 is an abundant number, since it is smaller than the sum of its proper divisors (1321027240).

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

1056821720 is a wasteful number, since it uses less digits than its factorization.

1056821720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26420554 (or 26420550 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 32.

The square root of 1056821720 is about 32508.7945024112. The cubic root of 1056821720 is about 1018.5927408783.

The spelling of 1056821720 in words is "one billion, fifty-six million, eight hundred twenty-one thousand, seven hundred twenty".