1644537401542 has 64 divisors (see below), whose sum is σ = 2950722846720. Its totient is φ = 672111738144.

The previous prime is 1644537401497. The next prime is 1644537401561. The reversal of 1644537401542 is 2451047354461.

It is a Harshad number since it is a multiple of its sum of digits (46).

It is a junction number, because it is equal to n+sod(n) for n = 1644537401492 and 1644537401501.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 196640253 + ... + 196648615.

It is an arithmetic number, because the mean of its divisors is an integer number (46105044480).

Almost surely, 2^{1644537401542} is an apocalyptic number.

1644537401542 is a deficient number, since it is larger than the sum of its proper divisors (1306185445178).

1644537401542 is a wasteful number, since it uses less digits than its factorization.

1644537401542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10177.

The product of its (nonzero) digits is 1612800, while the sum is 46.

The spelling of 1644537401542 in words is "one trillion, six hundred forty-four billion, five hundred thirty-seven million, four hundred one thousand, five hundred forty-two".