621466661 has 8 divisors (see below), whose sum is σ = 631761240. Its totient is φ = 611255808.

The previous prime is 621466639. The next prime is 621466663. The reversal of 621466661 is 166664126.

It can be written as a sum of positive squares in 4 ways, for example, as 396766561 + 224700100 = 19919^2 + 14990^2 .

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 621466661 - 2¹⁸ = 621204517 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621466663) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5876 + ... + 35741.

It is an arithmetic number, because the mean of its divisors is an integer number (78970155).

Almost surely, 2^621466661 is an apocalyptic number.

It is an amenable number.

621466661 is a deficient number, since it is larger than the sum of its proper divisors (10294579).

621466661 is a wasteful number, since it uses less digits than its factorization.

621466661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41863.

The product of its digits is 62208, while the sum is 38.

The square root of 621466661 is about 24929.2330608063. The cubic root of 621466661 is about 853.3737476621.

The spelling of 621466661 in words is "six hundred twenty-one million, four hundred sixty-six thousand, six hundred sixty-one".