1320687645 has 16 divisors (see below), whose sum is σ = 2124168192. Its totient is φ = 700677440.

The previous prime is 1320687547. The next prime is 1320687647. The reversal of 1320687645 is 5467860231.

It is not a de Polignac number, because 1320687645 - 2¹⁹ = 1320163357 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1320687597 and 1320687606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1320687647) 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, 227622 + ... + 233351.

It is an arithmetic number, because the mean of its divisors is an integer number (132760512).

Almost surely, 2^1320687645 is an apocalyptic number.

1320687645 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1320687645 is a deficient number, since it is larger than the sum of its proper divisors (803480547).

1320687645 is a wasteful number, since it uses less digits than its factorization.

1320687645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 461172.

The product of its (nonzero) digits is 241920, while the sum is 42.

The square root of 1320687645 is about 36341.2664198704. The cubic root of 1320687645 is about 1097.1517622573.

The spelling of 1320687645 in words is "one billion, three hundred twenty million, six hundred eighty-seven thousand, six hundred forty-five".