621141781 has 8 divisors (see below), whose sum is σ = 669243960. Its totient is φ = 573085632.

The previous prime is 621141779. The next prime is 621141799. The reversal of 621141781 is 187141126.

621141781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 205348900 + 415792881 = 14330^2 + 20391^2 .

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 621141781 - 2¹ = 621141779 is a prime.

It is a super-2 number, since 2×621141781² = 771634224207703922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621141281) 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, 19671 + ... + 40363.

It is an arithmetic number, because the mean of its divisors is an integer number (83655495).

Almost surely, 2^621141781 is an apocalyptic number.

It is an amenable number.

621141781 is a deficient number, since it is larger than the sum of its proper divisors (48102179).

621141781 is a wasteful number, since it uses less digits than its factorization.

621141781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23015.

The product of its digits is 2688, while the sum is 31.

The square root of 621141781 is about 24922.7161641744. The cubic root of 621141781 is about 853.2250175662.

The spelling of 621141781 in words is "six hundred twenty-one million, one hundred forty-one thousand, seven hundred eighty-one".