1645551134378 has 16 divisors (see below), whose sum is σ = 2475471718824. Its totient is φ = 820395449280.

The previous prime is 1645551134351. The next prime is 1645551134393. The reversal of 1645551134378 is 8734311555461.

It can be written as a sum of positive squares in 4 ways, for example, as 557257771009 + 1088293363369 = 746497^2 + 1043213^2 .

It is a super-2 number, since 2×1645551134378² (a number of 25 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1738448 + ... + 2512628.

Almost surely, 2^{1645551134378} is an apocalyptic number.

1645551134378 is a deficient number, since it is larger than the sum of its proper divisors (829920584446).

1645551134378 is a wasteful number, since it uses less digits than its factorization.

1645551134378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 777257.

The product of its digits is 6048000, while the sum is 53.

The spelling of 1645551134378 in words is "one trillion, six hundred forty-five billion, five hundred fifty-one million, one hundred thirty-four thousand, three hundred seventy-eight".