621005601 has 4 divisors (see below), whose sum is σ = 828007472. Its totient is φ = 414003732.

The previous prime is 621005587. The next prime is 621005653. The reversal of 621005601 is 106500126.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 621005601 - 2⁶ = 621005537 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (621005201) 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, 103500931 + ... + 103500936.

It is an arithmetic number, because the mean of its divisors is an integer number (207001868).

Almost surely, 2^621005601 is an apocalyptic number.

It is an amenable number.

621005601 is a deficient number, since it is larger than the sum of its proper divisors (207001871).

621005601 is a wasteful number, since it uses less digits than its factorization.

621005601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207001870.

The product of its (nonzero) digits is 360, while the sum is 21.

The square root of 621005601 is about 24919.9839686947. The cubic root of 621005601 is about 853.1626589234.

Adding to 621005601 its reverse (106500126), we get a palindrome (727505727).

The spelling of 621005601 in words is "six hundred twenty-one million, five thousand, six hundred one".