1345320820 has 24 divisors (see below), whose sum is σ = 2845801224. Its totient is φ = 534199296.

The previous prime is 1345320811. The next prime is 1345320827. The reversal of 1345320820 is 280235431.

It can be written as a sum of positive squares in 4 ways, for example, as 499790736 + 845530084 = 22356^2 + 29078^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1345320827) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 242757 + ... + 248236.

It is an arithmetic number, because the mean of its divisors is an integer number (118575051).

Almost surely, 2^1345320820 is an apocalyptic number.

1345320820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1345320820 is an abundant number, since it is smaller than the sum of its proper divisors (1500480404).

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

1345320820 is a wasteful number, since it uses less digits than its factorization.

1345320820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 491139 (or 491137 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 1345320820 is about 36678.6152955643. The cubic root of 1345320820 is about 1103.9310643174.

The spelling of 1345320820 in words is "one billion, three hundred forty-five million, three hundred twenty thousand, eight hundred twenty".