621661544 has 16 divisors (see below), whose sum is σ = 1332132000. Its totient is φ = 266426352.

The previous prime is 621661543. The next prime is 621661561. The reversal of 621661544 is 445166126.

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (621661543) 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, 5550494 + ... + 5550605.

It is an arithmetic number, because the mean of its divisors is an integer number (83258250).

Almost surely, 2^621661544 is an apocalyptic number.

It is an amenable number.

621661544 is an abundant number, since it is smaller than the sum of its proper divisors (710470456).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

621661544 is a wasteful number, since it uses less digits than its factorization.

621661544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11101112 (or 11101108 counting only the distinct ones).

The product of its digits is 34560, while the sum is 35.

The square root of 621661544 is about 24933.1414787628. The cubic root of 621661544 is about 853.4629402477.

The spelling of 621661544 in words is "six hundred twenty-one million, six hundred sixty-one thousand, five hundred forty-four".