1656139207 has 4 divisors (see below), whose sum is σ = 1665712440. Its totient is φ = 1646565976.

The previous prime is 1656139189. The next prime is 1656139213. The reversal of 1656139207 is 7029316561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7029316561 = 51839 ⋅135599.

It is a cyclic number.

It is not a de Polignac number, because 1656139207 - 2¹¹ = 1656137159 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 1656139207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1656139907) 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, 4786357 + ... + 4786702.

It is an arithmetic number, because the mean of its divisors is an integer number (416428110).

Almost surely, 2^1656139207 is an apocalyptic number.

1656139207 is a deficient number, since it is larger than the sum of its proper divisors (9573233).

1656139207 is an equidigital number, since it uses as much as digits as its factorization.

1656139207 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9573232.

The product of its (nonzero) digits is 68040, while the sum is 40.

The square root of 1656139207 is about 40695.6902755071. The cubic root of 1656139207 is about 1183.1294902376.

The spelling of 1656139207 in words is "one billion, six hundred fifty-six million, one hundred thirty-nine thousand, two hundred seven".