401421661780 has 48 divisors (see below), whose sum is σ = 857729633040. Its totient is φ = 157765939200.

The previous prime is 401421661757. The next prime is 401421661783. The reversal of 401421661780 is 87166124104.

It can be written as a sum of positive squares in 8 ways, for example, as 67111047364 + 334310614416 = 259058^2 + 578196^2 .

It is a super-2 number, since 2×401421661780² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (401421661783) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 956290 + ... + 1310470.

It is an arithmetic number, because the mean of its divisors is an integer number (17869367355).

Almost surely, 2^401421661780 is an apocalyptic number.

It is an amenable number.

401421661780 is an abundant number, since it is smaller than the sum of its proper divisors (456307971260).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

401421661780 is a wasteful number, since it uses less digits than its factorization.

401421661780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 355180 (or 355178 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 40.

Adding to 401421661780 its reverse (87166124104), we get a palindrome (488587785884).

The spelling of 401421661780 in words is "four hundred one billion, four hundred twenty-one million, six hundred sixty-one thousand, seven hundred eighty".