400220101 has 4 divisors (see below), whose sum is σ = 400260204. Its totient is φ = 400180000.

The previous prime is 400220089. The next prime is 400220111. The reversal of 400220101 is 101022004.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 76580001 + 323640100 = 8751^2 + 17990^2 .

It is a cyclic number.

It is not a de Polignac number, because 400220101 - 2⁷ = 400219973 is a prime.

It is a super-2 number, since 2×400220101² = 320352258488900402, 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 (400220111) 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, 8001 + ... + 29401.

It is an arithmetic number, because the mean of its divisors is an integer number (100065051).

Almost surely, 2^400220101 is an apocalyptic number.

It is an amenable number.

400220101 is a deficient number, since it is larger than the sum of its proper divisors (40103).

400220101 is a wasteful number, since it uses less digits than its factorization.

400220101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40102.

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 400220101 is about 20005.5017682636. The cubic root of 400220101 is about 736.9414181175.

Adding to 400220101 its reverse (101022004), we get a palindrome (501242105).

The spelling of 400220101 in words is "four hundred million, two hundred twenty thousand, one hundred one".