400400101 has 4 divisors (see below), whose sum is σ = 403087500. Its totient is φ = 397712704.

The previous prime is 400400081. The next prime is 400400113. The reversal of 400400101 is 101004004.

It is a Cunningham number, because it is equal to 20010²+1.

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 46922500 + 353477601 = 6850^2 + 18801^2 .

It is a cyclic number.

It is not a de Polignac number, because 400400101 - 2¹³ = 400391909 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400400131) 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, 1343476 + ... + 1343773.

It is an arithmetic number, because the mean of its divisors is an integer number (100771875).

Almost surely, 2^400400101 is an apocalyptic number.

It is an amenable number.

400400101 is a deficient number, since it is larger than the sum of its proper divisors (2687399).

400400101 is a wasteful number, since it uses less digits than its factorization.

400400101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2687398.

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

The square root of 400400101 is about 20010.0000249875. Note that the first 4 decimals coincide. The cubic root of 400400101 is about 737.0518819793.

Adding to 400400101 its reverse (101004004), we get a palindrome (501404105).

The spelling of 400400101 in words is "four hundred million, four hundred thousand, one hundred one".