401278517 has 6 divisors (see below), whose sum is σ = 403863222. Its totient is φ = 398697032.

The previous prime is 401278487. The next prime is 401278541. The reversal of 401278517 is 715872104.

It can be written as a sum of positive squares in only one way, i.e., 392000401 + 9278116 = 19799^2 + 3046^2 .

It is not a de Polignac number, because 401278517 - 2⁸ = 401278261 is a prime.

It is a super-2 number, since 2×401278517² = 322048896411438578, 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 (401278547) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 262718 + ... + 264240.

It is an arithmetic number, because the mean of its divisors is an integer number (67310537).

Almost surely, 2^401278517 is an apocalyptic number.

It is an amenable number.

401278517 is a deficient number, since it is larger than the sum of its proper divisors (2584705).

401278517 is an frugal number, since it uses more digits than its factorization.

401278517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3219 (or 1696 counting only the distinct ones).

The product of its (nonzero) digits is 15680, while the sum is 35.

The square root of 401278517 is about 20031.9374250221. The cubic root of 401278517 is about 737.5904809796.

The spelling of 401278517 in words is "four hundred one million, two hundred seventy-eight thousand, five hundred seventeen".