401665553918 has 16 divisors (see below), whose sum is σ = 626756130000. Its totient is φ = 192824221632.

The previous prime is 401665553893. The next prime is 401665553941. The reversal of 401665553918 is 819355566104.

It is a happy number.

It is a super-2 number, since 2×401665553918² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 401665553918.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19333943 + ... + 19354706.

It is an arithmetic number, because the mean of its divisors is an integer number (39172258125).

Almost surely, 2^401665553918 is an apocalyptic number.

401665553918 is a deficient number, since it is larger than the sum of its proper divisors (225090576082).

401665553918 is a wasteful number, since it uses less digits than its factorization.

401665553918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38688859.

The product of its (nonzero) digits is 3888000, while the sum is 53.

The spelling of 401665553918 in words is "four hundred one billion, six hundred sixty-five million, five hundred fifty-three thousand, nine hundred eighteen".