621403681 has 8 divisors (see below), whose sum is σ = 624605184. Its totient is φ = 618209760.

The previous prime is 621403639. The next prime is 621403687. The reversal of 621403681 is 186304126.

It is a happy number.

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 621403681 - 2¹¹ = 621401633 is a prime.

It is a super-2 number, since 2×621403681² = 772285069520699522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (621403687) 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, 229920 + ... + 232606.

It is an arithmetic number, because the mean of its divisors is an integer number (78075648).

Almost surely, 2^621403681 is an apocalyptic number.

It is an amenable number.

621403681 is a deficient number, since it is larger than the sum of its proper divisors (3201503).

621403681 is a wasteful number, since it uses less digits than its factorization.

621403681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3791.

The product of its (nonzero) digits is 6912, while the sum is 31.

The square root of 621403681 is about 24927.9698531589. The cubic root of 621403681 is about 853.3449194628.

The spelling of 621403681 in words is "six hundred twenty-one million, four hundred three thousand, six hundred eighty-one".