621621001 has 8 divisors (see below), whose sum is σ = 624342600. Its totient is φ = 618905472.

The previous prime is 621620999. The next prime is 621621037. The reversal of 621621001 is 100126126.

It can be written as a sum of positive squares in 4 ways, for example, as 277555600 + 344065401 = 16660^2 + 18549^2 .

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 621621001 - 2¹ = 621620999 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 621621001.

It is not an unprimeable number, because it can be changed into a prime (621621041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 415611 + ... + 417103.

It is an arithmetic number, because the mean of its divisors is an integer number (78042825).

Almost surely, 2^621621001 is an apocalyptic number.

It is an amenable number.

621621001 is a deficient number, since it is larger than the sum of its proper divisors (2721599).

621621001 is a wasteful number, since it uses less digits than its factorization.

621621001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3035.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 621621001 is about 24932.3284311755. The cubic root of 621621001 is about 853.4443863682. Note that the first 3 decimals are identical.

Adding to 621621001 its reverse (100126126), we get a palindrome (721747127).

The spelling of 621621001 in words is "six hundred twenty-one million, six hundred twenty-one thousand, one".