400121652 has 72 divisors (see below), whose sum is σ = 1094192064. Its totient is φ = 113463168.

The previous prime is 400121641. The next prime is 400121693. The reversal of 400121652 is 256121004.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 78073 + ... + 83039.

It is an arithmetic number, because the mean of its divisors is an integer number (15197112).

Almost surely, 2^400121652 is an apocalyptic number.

400121652 is a gapful number since it is divisible by the number (42) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 400121652, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (547096032).

400121652 is an abundant number, since it is smaller than the sum of its proper divisors (694070412).

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

400121652 is a wasteful number, since it uses less digits than its factorization.

400121652 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5125 (or 5116 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 400121652 is about 20003.0410687975. The cubic root of 400121652 is about 736.8809871237.

Adding to 400121652 its reverse (256121004), we get a palindrome (656242656).

The spelling of 400121652 in words is "four hundred million, one hundred twenty-one thousand, six hundred fifty-two".