621305921739 has 4 divisors (see below), whose sum is σ = 828407895656. Its totient is φ = 414203947824.

The previous prime is 621305921723. The next prime is 621305921767. The reversal of 621305921739 is 937129503126.

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

It is not a de Polignac number, because 621305921739 - 2⁴ = 621305921723 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (621305921039) 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, 103550986954 + ... + 103550986959.

It is an arithmetic number, because the mean of its divisors is an integer number (207101973914).

Almost surely, 2^621305921739 is an apocalyptic number.

621305921739 is a deficient number, since it is larger than the sum of its proper divisors (207101973917).

621305921739 is a wasteful number, since it uses less digits than its factorization.

621305921739 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207101973916.

The product of its (nonzero) digits is 612360, while the sum is 48.

The spelling of 621305921739 in words is "six hundred twenty-one billion, three hundred five million, nine hundred twenty-one thousand, seven hundred thirty-nine".