401779111709221 has 4 divisors (see below), whose sum is σ = 403998885807244. Its totient is φ = 399559337611200.

The previous prime is 401779111709197. The next prime is 401779111709231. The reversal of 401779111709221 is 122907111977104.

It is a happy number.

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 205317231921025 + 196461879788196 = 14328895^2 + 14016486^2 .

It is a cyclic number.

It is not a de Polignac number, because 401779111709221 - 2⁷ = 401779111709093 is a prime.

It is a super-3 number, since 3×401779111709221³ (a number of 45 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (401779111709231) 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, 1109887048740 + ... + 1109887049101.

It is an arithmetic number, because the mean of its divisors is an integer number (100999721451811).

Almost surely, 2^{401779111709221} is an apocalyptic number.

It is an amenable number.

401779111709221 is a deficient number, since it is larger than the sum of its proper divisors (2219774098023).

401779111709221 is a wasteful number, since it uses less digits than its factorization.

401779111709221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2219774098022.

The product of its (nonzero) digits is 444528, while the sum is 52.

The spelling of 401779111709221 in words is "four hundred one trillion, seven hundred seventy-nine billion, one hundred eleven million, seven hundred nine thousand, two hundred twenty-one".