401978871 has 48 divisors (see below), whose sum is σ = 682007040. Its totient is φ = 223404480.

The previous prime is 401978869. The next prime is 401978873. The reversal of 401978871 is 178879104.

It is an interprime number because it is at equal distance from previous prime (401978869) and next prime (401978873).

It is not a de Polignac number, because 401978871 - 2¹ = 401978869 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (401978873) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 436950 + ... + 437868.

It is an arithmetic number, because the mean of its divisors is an integer number (14208480).

Almost surely, 2^401978871 is an apocalyptic number.

401978871 is a deficient number, since it is larger than the sum of its proper divisors (280028169).

401978871 is a wasteful number, since it uses less digits than its factorization.

401978871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1116 (or 1113 counting only the distinct ones).

The product of its (nonzero) digits is 112896, while the sum is 45.

The square root of 401978871 is about 20049.4107394706. The cubic root of 401978871 is about 738.0193387313.

The spelling of 401978871 in words is "four hundred one million, nine hundred seventy-eight thousand, eight hundred seventy-one".