420878631 has 4 divisors (see below), whose sum is σ = 561171512. Its totient is φ = 280585752.

The previous prime is 420878617. The next prime is 420878651. The reversal of 420878631 is 136878024.

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

It is not a de Polignac number, because 420878631 - 2¹¹ = 420876583 is a prime.

It is a super-2 number, since 2×420878631² = 354277644064868322, which contains 22 as substring.

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 420878631.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (420878611) 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, 70146436 + ... + 70146441.

It is an arithmetic number, because the mean of its divisors is an integer number (140292878).

Almost surely, 2^420878631 is an apocalyptic number.

420878631 is a deficient number, since it is larger than the sum of its proper divisors (140292881).

420878631 is a wasteful number, since it uses less digits than its factorization.

420878631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140292880.

The product of its (nonzero) digits is 64512, while the sum is 39.

The square root of 420878631 is about 20515.3267339324. The cubic root of 420878631 is about 749.4090936730.

The spelling of 420878631 in words is "four hundred twenty million, eight hundred seventy-eight thousand, six hundred thirty-one".