1051720520565 has 128 divisors (see below), whose sum is σ = 2097864437760. Its totient is φ = 442602547200.

The previous prime is 1051720520503. The next prime is 1051720520567. The reversal of 1051720520565 is 5650250271501.

It is not a de Polignac number, because 1051720520565 - 2¹⁴ = 1051720504181 is a prime.

It is a super-2 number, since 2×1051720520565² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1051720520567) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 2730105 + ... + 3091425.

It is an arithmetic number, because the mean of its divisors is an integer number (16389565920).

Almost surely, 2^{1051720520565} is an apocalyptic number.

1051720520565 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1051720520565 is a deficient number, since it is larger than the sum of its proper divisors (1046143917195).

1051720520565 is a wasteful number, since it uses less digits than its factorization.

1051720520565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 361435.

The product of its (nonzero) digits is 105000, while the sum is 39.

The spelling of 1051720520565 in words is "one trillion, fifty-one billion, seven hundred twenty million, five hundred twenty thousand, five hundred sixty-five".