1646642556101 has 4 divisors (see below), whose sum is σ = 1646645169312. Its totient is φ = 1646639942892.

The previous prime is 1646642556089. The next prime is 1646642556107. The reversal of 1646642556101 is 1016552466461.

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 a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1646642556101 is a prime.

It is a super-2 number, since 2×1646642556101² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1646642556107) 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, 284126 + ... + 1836848.

It is an arithmetic number, because the mean of its divisors is an integer number (411661292328).

Almost surely, 2^{1646642556101} is an apocalyptic number.

It is an amenable number.

1646642556101 is a deficient number, since it is larger than the sum of its proper divisors (2613211).

1646642556101 is a wasteful number, since it uses less digits than its factorization.

1646642556101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2613210.

The product of its (nonzero) digits is 1036800, while the sum is 47.

The spelling of 1646642556101 in words is "one trillion, six hundred forty-six billion, six hundred forty-two million, five hundred fifty-six thousand, one hundred one".