1645665215051 has 16 divisors (see below), whose sum is σ = 1933412398848. Its totient is φ = 1380946749600.

The previous prime is 1645665214997. The next prime is 1645665215069. The reversal of 1645665215051 is 1505125665461.

It is not a de Polignac number, because 1645665215051 - 2¹⁸ = 1645664952907 is a prime.

It is a super-3 number, since 3×1645665215051³ (a number of 38 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1645665214987 and 1645665215005.

It is not an unprimeable number, because it can be changed into a prime (1645665215071) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8056856 + ... + 8258586.

It is an arithmetic number, because the mean of its divisors is an integer number (120838274928).

Almost surely, 2^{1645665215051} is an apocalyptic number.

1645665215051 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1645665215051 is a deficient number, since it is larger than the sum of its proper divisors (287747183797).

1645665215051 is a wasteful number, since it uses less digits than its factorization.

1645665215051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 258802.

The product of its (nonzero) digits is 1080000, while the sum is 47.

The spelling of 1645665215051 in words is "one trillion, six hundred forty-five billion, six hundred sixty-five million, two hundred fifteen thousand, fifty-one".