402440420391 has 4 divisors (see below), whose sum is σ = 536587227192. Its totient is φ = 268293613592.

The previous prime is 402440420381. The next prime is 402440420399. The reversal of 402440420391 is 193024044204.

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 402440420391 - 2⁹ = 402440419879 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (402440420399) 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, 67073403396 + ... + 67073403401.

It is an arithmetic number, because the mean of its divisors is an integer number (134146806798).

Almost surely, 2^402440420391 is an apocalyptic number.

402440420391 is a deficient number, since it is larger than the sum of its proper divisors (134146806801).

402440420391 is a wasteful number, since it uses less digits than its factorization.

402440420391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134146806800.

The product of its (nonzero) digits is 27648, while the sum is 33.

Adding to 402440420391 its reverse (193024044204), we get a palindrome (595464464595).

The spelling of 402440420391 in words is "four hundred two billion, four hundred forty million, four hundred twenty thousand, three hundred ninety-one".