1656651601 has 4 divisors (see below), whose sum is σ = 1807256304. Its totient is φ = 1506046900.

The previous prime is 1656651589. The next prime is 1656651631. The reversal of 1656651601 is 1061566561.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1061566561 = 11 ⋅96506051.

It is a cyclic number.

It is not a de Polignac number, because 1656651601 - 2¹³ = 1656643409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1656651631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 75302335 + ... + 75302356.

It is an arithmetic number, because the mean of its divisors is an integer number (451814076).

Almost surely, 2^1656651601 is an apocalyptic number.

1656651601 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1656651601 is a deficient number, since it is larger than the sum of its proper divisors (150604703).

1656651601 is a wasteful number, since it uses less digits than its factorization.

1656651601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150604702.

The product of its (nonzero) digits is 32400, while the sum is 37.

The square root of 1656651601 is about 40701.9852218537. The cubic root of 1656651601 is about 1183.2514940602.

The spelling of 1656651601 in words is "one billion, six hundred fifty-six million, six hundred fifty-one thousand, six hundred one".