401688945 has 24 divisors (see below), whose sum is σ = 795727296. Its totient is φ = 183629088.

The previous prime is 401688943. The next prime is 401688977. The reversal of 401688945 is 549886104.

It is not a de Polignac number, because 401688945 - 2¹ = 401688943 is a prime.

It is a super-2 number, since 2×401688945² = 322708017070426050, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 401688945.

It is not an unprimeable number, because it can be changed into a prime (401688943) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 637287 + ... + 637916.

It is an arithmetic number, because the mean of its divisors is an integer number (33155304).

Almost surely, 2^401688945 is an apocalyptic number.

401688945 is a gapful number since it is divisible by the number (45) formed by its first and last digit.

It is an amenable number.

401688945 is a deficient number, since it is larger than the sum of its proper divisors (394038351).

401688945 is a wasteful number, since it uses less digits than its factorization.

401688945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1275221 (or 1275218 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 45.

The square root of 401688945 is about 20042.1791479869. The cubic root of 401688945 is about 737.8418646792.

The spelling of 401688945 in words is "four hundred one million, six hundred eighty-eight thousand, nine hundred forty-five".