1621345747 has 4 divisors (see below), whose sum is σ = 1852966576. Its totient is φ = 1389724920.

The previous prime is 1621345727. The next prime is 1621345799. The reversal of 1621345747 is 7475431261.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1621345747 - 2⁷ = 1621345619 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1621345727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 115810404 + ... + 115810417.

It is an arithmetic number, because the mean of its divisors is an integer number (463241644).

Almost surely, 2^1621345747 is an apocalyptic number.

1621345747 is a deficient number, since it is larger than the sum of its proper divisors (231620829).

1621345747 is an equidigital number, since it uses as much as digits as its factorization.

1621345747 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231620828.

The product of its digits is 141120, while the sum is 40.

The square root of 1621345747 is about 40265.9378010745. The cubic root of 1621345747 is about 1174.7854135369.

The spelling of 1621345747 in words is "one billion, six hundred twenty-one million, three hundred forty-five thousand, seven hundred forty-seven".