1656205638 has 16 divisors (see below), whose sum is σ = 3368554560. Its totient is φ = 542711336.

The previous prime is 1656205627. The next prime is 1656205667. The reversal of 1656205638 is 8365026561.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 1656205638.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2338920 + ... + 2339627.

It is an arithmetic number, because the mean of its divisors is an integer number (210534660).

Almost surely, 2^1656205638 is an apocalyptic number.

1656205638 is an abundant number, since it is smaller than the sum of its proper divisors (1712348922).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1656205638 is a wasteful number, since it uses less digits than its factorization.

1656205638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4678611.

The product of its (nonzero) digits is 259200, while the sum is 42.

The square root of 1656205638 is about 40696.5064594002. The cubic root of 1656205638 is about 1183.1453092428.

The spelling of 1656205638 in words is "one billion, six hundred fifty-six million, two hundred five thousand, six hundred thirty-eight".