1071856820 has 24 divisors (see below), whose sum is σ = 2328517800. Its totient is φ = 413958272.

The previous prime is 1071856813. The next prime is 1071856847. The reversal of 1071856820 is 286581701.

It can be written as a sum of positive squares in 4 ways, for example, as 60871204 + 1010985616 = 7802^2 + 31796^2 .

It is a super-2 number, since 2×1071856820² = 2297754085161024800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 923435 + ... + 924594.

It is an arithmetic number, because the mean of its divisors is an integer number (97021575).

Almost surely, 2^1071856820 is an apocalyptic number.

1071856820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1071856820 is an abundant number, since it is smaller than the sum of its proper divisors (1256660980).

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

1071856820 is a wasteful number, since it uses less digits than its factorization.

1071856820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1848067 (or 1848065 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 38.

The square root of 1071856820 is about 32739.2244868445. The cubic root of 1071856820 is about 1023.4004223671.

It can be divided in two parts, 1071 and 856820, that multiplied together give a triangular number (917654220 = T₄₂₈₄₀).

The spelling of 1071856820 in words is "one billion, seventy-one million, eight hundred fifty-six thousand, eight hundred twenty".