402672421 has 4 divisors (see below), whose sum is σ = 426359052. Its totient is φ = 378985792.

The previous prime is 402672419. The next prime is 402672427. The reversal of 402672421 is 124276204.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 275095396 + 127577025 = 16586^2 + 11295^2 .

It is a cyclic number.

It is not a de Polignac number, because 402672421 - 2¹ = 402672419 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 402672421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (402672427) 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, 11843290 + ... + 11843323.

It is an arithmetic number, because the mean of its divisors is an integer number (106589763).

Almost surely, 2^402672421 is an apocalyptic number.

It is an amenable number.

402672421 is a deficient number, since it is larger than the sum of its proper divisors (23686631).

402672421 is a wasteful number, since it uses less digits than its factorization.

402672421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23686630.

The product of its (nonzero) digits is 5376, while the sum is 28.

The square root of 402672421 is about 20066.6993050676. The cubic root of 402672421 is about 738.4435394855.

The spelling of 402672421 in words is "four hundred two million, six hundred seventy-two thousand, four hundred twenty-one".