1621440345 has 64 divisors (see below), whose sum is σ = 3044321280. Its totient is φ = 721502208.

The previous prime is 1621440341. The next prime is 1621440377. The reversal of 1621440345 is 5430441261.

It is not a de Polignac number, because 1621440345 - 2² = 1621440341 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1621440341) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2108121 + ... + 2108889.

It is an arithmetic number, because the mean of its divisors is an integer number (47567520).

Almost surely, 2^1621440345 is an apocalyptic number.

1621440345 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1621440345 is a deficient number, since it is larger than the sum of its proper divisors (1422880935).

1621440345 is a wasteful number, since it uses less digits than its factorization.

1621440345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1294.

The product of its (nonzero) digits is 11520, while the sum is 30.

The square root of 1621440345 is about 40267.1124492432. The cubic root of 1621440345 is about 1174.8082608515.

The spelling of 1621440345 in words is "one billion, six hundred twenty-one million, four hundred forty thousand, three hundred forty-five".