402439649 has 4 divisors (see below), whose sum is σ = 409260720. Its totient is φ = 395618580.

The previous prime is 402439637. The next prime is 402439673. The reversal of 402439649 is 946934204.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 402439649 - 2⁴ = 402439633 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (402439619) 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, 3410447 + ... + 3410564.

It is an arithmetic number, because the mean of its divisors is an integer number (102315180).

Almost surely, 2^402439649 is an apocalyptic number.

It is an amenable number.

402439649 is a deficient number, since it is larger than the sum of its proper divisors (6821071).

402439649 is an equidigital number, since it uses as much as digits as its factorization.

402439649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6821070.

The product of its (nonzero) digits is 186624, while the sum is 41.

The square root of 402439649 is about 20060.8985092892. The cubic root of 402439649 is about 738.3012218906.

The spelling of 402439649 in words is "four hundred two million, four hundred thirty-nine thousand, six hundred forty-nine".