405252421 has 4 divisors (see below), whose sum is σ = 463145632. Its totient is φ = 347359212.

The previous prime is 405252403. The next prime is 405252427. The reversal of 405252421 is 124252504.

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 405252421 - 2⁵ = 405252389 is a prime.

It is a super-2 number, since 2×405252421² = 328459049452722482, which 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 (405252427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28946595 + ... + 28946608.

It is an arithmetic number, because the mean of its divisors is an integer number (115786408).

Almost surely, 2^405252421 is an apocalyptic number.

It is an amenable number.

405252421 is a deficient number, since it is larger than the sum of its proper divisors (57893211).

405252421 is an equidigital number, since it uses as much as digits as its factorization.

405252421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57893210.

The product of its (nonzero) digits is 3200, while the sum is 25.

The square root of 405252421 is about 20130.8822707799. The cubic root of 405252421 is about 740.0172999364.

The spelling of 405252421 in words is "four hundred five million, two hundred fifty-two thousand, four hundred twenty-one".