1656501001 has 4 divisors (see below), whose sum is σ = 1657647232. Its totient is φ = 1655354772.

The previous prime is 1656500987. The next prime is 1656501017. The reversal of 1656501001 is 1001056561.

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: 1001056561 = 1987 ⋅503803.

It is a cyclic number.

It is not a de Polignac number, because 1656501001 - 2¹³ = 1656492809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1656501701) 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, 570945 + ... + 573838.

It is an arithmetic number, because the mean of its divisors is an integer number (414411808).

Almost surely, 2^1656501001 is an apocalyptic number.

It is an amenable number.

1656501001 is a deficient number, since it is larger than the sum of its proper divisors (1146231).

1656501001 is a wasteful number, since it uses less digits than its factorization.

1656501001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1146230.

The product of its (nonzero) digits is 900, while the sum is 25.

The square root of 1656501001 is about 40700.1351471958. The cubic root of 1656501001 is about 1183.2156379846.

Adding to 1656501001 its reverse (1001056561), we get a palindrome (2657557562).

The spelling of 1656501001 in words is "one billion, six hundred fifty-six million, five hundred one thousand, one".