2656821487 has 4 divisors (see below), whose sum is σ = 2657055960. Its totient is φ = 2656587016.

The previous prime is 2656821439. The next prime is 2656821493. The reversal of 2656821487 is 7841286562.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2656821487 - 2¹⁹ = 2656297199 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2656821487.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2656821437) 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, 99328 + ... + 123205.

It is an arithmetic number, because the mean of its divisors is an integer number (664263990).

Almost surely, 2^2656821487 is an apocalyptic number.

2656821487 is a deficient number, since it is larger than the sum of its proper divisors (234473).

2656821487 is a wasteful number, since it uses less digits than its factorization.

2656821487 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234472.

The product of its digits is 1290240, while the sum is 49.

The square root of 2656821487 is about 51544.3642603146. The cubic root of 2656821487 is about 1385.0138776212.

The spelling of 2656821487 in words is "two billion, six hundred fifty-six million, eight hundred twenty-one thousand, four hundred eighty-seven".