421729815 has 16 divisors (see below), whose sum is σ = 726673248. Its totient is φ = 207620736.

The previous prime is 421729807. The next prime is 421729837. The reversal of 421729815 is 518927124.

It is not a de Polignac number, because 421729815 - 2³ = 421729807 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 1081164 + ... + 1081553.

It is an arithmetic number, because the mean of its divisors is an integer number (45417078).

Almost surely, 2^421729815 is an apocalyptic number.

421729815 is a deficient number, since it is larger than the sum of its proper divisors (304943433).

421729815 is a wasteful number, since it uses less digits than its factorization.

421729815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2162738.

The product of its digits is 40320, while the sum is 39.

The square root of 421729815 is about 20536.0613312290. The cubic root of 421729815 is about 749.9139545731.

It can be divided in two parts, 421 and 729815, that added together give a triangular number (730236 = T₁₂₀₈).

The spelling of 421729815 in words is "four hundred twenty-one million, seven hundred twenty-nine thousand, eight hundred fifteen".