401761561 has 4 divisors (see below), whose sum is σ = 425394612. Its totient is φ = 378128512.

The previous prime is 401761553. The next prime is 401761589. The reversal of 401761561 is 165167104.

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

It can be written as a sum of positive squares in 2 ways, for example, as 107433225 + 294328336 = 10365^2 + 17156^2 .

It is a cyclic number.

It is not a de Polignac number, because 401761561 - 2³ = 401761553 is a prime.

It is a super-2 number, since 2×401761561² = 322824703794313442, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (401761541) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11816500 + ... + 11816533.

It is an arithmetic number, because the mean of its divisors is an integer number (106348653).

Almost surely, 2^401761561 is an apocalyptic number.

It is an amenable number.

401761561 is a deficient number, since it is larger than the sum of its proper divisors (23633051).

401761561 is a wasteful number, since it uses less digits than its factorization.

401761561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23633050.

The product of its (nonzero) digits is 5040, while the sum is 31.

The square root of 401761561 is about 20043.9906455775. The cubic root of 401761561 is about 737.8863235382.

The spelling of 401761561 in words is "four hundred one million, seven hundred sixty-one thousand, five hundred sixty-one".