621723421 has 8 divisors (see below), whose sum is σ = 682166304. Its totient is φ = 561934320.

The previous prime is 621723409. The next prime is 621723449. The reversal of 621723421 is 124327126.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 621723421 - 2¹³ = 621715229 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 621723421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621723461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 161451 + ... + 165256.

It is an arithmetic number, because the mean of its divisors is an integer number (85270788).

Almost surely, 2^621723421 is an apocalyptic number.

It is an amenable number.

621723421 is a deficient number, since it is larger than the sum of its proper divisors (60442883).

621723421 is a wasteful number, since it uses less digits than its factorization.

621723421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 326891.

The product of its digits is 4032, while the sum is 28.

The square root of 621723421 is about 24934.3823063656. The cubic root of 621723421 is about 853.4912557488.

The spelling of 621723421 in words is "six hundred twenty-one million, seven hundred twenty-three thousand, four hundred twenty-one".