1646551020407 has 4 divisors (see below), whose sum is σ = 1665051593760. Its totient is φ = 1628050447056.

The previous prime is 1646551020353. The next prime is 1646551020421. The reversal of 1646551020407 is 7040201556461.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1646551020407 - 2¹⁶ = 1646550954871 is a prime.

It is a super-2 number, since 2×1646551020407² (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 (1646551029407) 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, 9250286543 + ... + 9250286720.

It is an arithmetic number, because the mean of its divisors is an integer number (416262898440).

Almost surely, 2^{1646551020407} is an apocalyptic number.

1646551020407 is a deficient number, since it is larger than the sum of its proper divisors (18500573353).

1646551020407 is an equidigital number, since it uses as much as digits as its factorization.

1646551020407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18500573352.

The product of its (nonzero) digits is 201600, while the sum is 41.

Adding to 1646551020407 its reverse (7040201556461), we get a palindrome (8686752576868).

The spelling of 1646551020407 in words is "one trillion, six hundred forty-six billion, five hundred fifty-one million, twenty thousand, four hundred seven".