401407778 has 18 divisors (see below), whose sum is σ = 623525553. Its totient is φ = 193804560.

The previous prime is 401407759. The next prime is 401407793. The reversal of 401407778 is 877704104.

It can be written as a sum of positive squares in 2 ways, for example, as 337934689 + 63473089 = 18383^2 + 7967^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=14167.

It is a super-2 number, since 2×401407778² = 322256408477794568, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 878126 + ... + 878582.

Almost surely, 2^401407778 is an apocalyptic number.

401407778 is a deficient number, since it is larger than the sum of its proper divisors (222117775).

401407778 is an frugal number, since it uses more digits than its factorization.

401407778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 978 (or 490 counting only the distinct ones).

The product of its (nonzero) digits is 43904, while the sum is 38.

The square root of 401407778 is about 20035.1635381396. The cubic root of 401407778 is about 737.6696707391.

The spelling of 401407778 in words is "four hundred one million, four hundred seven thousand, seven hundred seventy-eight".