611643021 has 24 divisors (see below), whose sum is σ = 897960672. Its totient is φ = 370048800.

The previous prime is 611643001. The next prime is 611643023. The reversal of 611643021 is 120346116.

It is not a de Polignac number, because 611643021 - 2¹¹ = 611640973 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 611642982 and 611643000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (611643023) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 284611 + ... + 286751.

It is an arithmetic number, because the mean of its divisors is an integer number (37415028).

Almost surely, 2^611643021 is an apocalyptic number.

It is an amenable number.

611643021 is a deficient number, since it is larger than the sum of its proper divisors (286317651).

611643021 is a wasteful number, since it uses less digits than its factorization.

611643021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2953 (or 2942 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 611643021 is about 24731.4176908644. The cubic root of 611643021 is about 848.8533655560.

Adding to 611643021 its reverse (120346116), we get a palindrome (731989137).

The spelling of 611643021 in words is "six hundred eleven million, six hundred forty-three thousand, twenty-one".