2604661821 has 12 divisors (see below), whose sum is σ = 3765361600. Its totient is φ = 1735023240.

The previous prime is 2604661811. The next prime is 2604661823. The reversal of 2604661821 is 1281664062.

It is not a de Polignac number, because 2604661821 - 2⁵ = 2604661789 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 (2604661823) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 106471 + ... + 128628.

Almost surely, 2^2604661821 is an apocalyptic number.

It is an amenable number.

2604661821 is a deficient number, since it is larger than the sum of its proper divisors (1160699779).

2604661821 is a wasteful number, since it uses less digits than its factorization.

2604661821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236336 (or 236333 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 2604661821 is about 51035.8875792319. The cubic root of 2604661821 is about 1375.8902129047.

The spelling of 2604661821 in words is "two billion, six hundred four million, six hundred sixty-one thousand, eight hundred twenty-one".