840406353623 has 4 divisors (see below), whose sum is σ = 840442413408. Its totient is φ = 840370293840.

The previous prime is 840406353607. The next prime is 840406353653. The reversal of 840406353623 is 326353604048.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 840406353623 - 2⁴ = 840406353607 is a prime.

It is a super-2 number, since 2×840406353623² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (840406353653) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17994911 + ... + 18041552.

It is an arithmetic number, because the mean of its divisors is an integer number (210110603352).

Almost surely, 2^840406353623 is an apocalyptic number.

840406353623 is a deficient number, since it is larger than the sum of its proper divisors (36059785).

840406353623 is a wasteful number, since it uses less digits than its factorization.

840406353623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36059784.

The product of its (nonzero) digits is 1244160, while the sum is 44.

The spelling of 840406353623 in words is "eight hundred forty billion, four hundred six million, three hundred fifty-three thousand, six hundred twenty-three".