400651321572 has 120 divisors (see below), whose sum is σ = 1065692859000. Its totient is φ = 131220311040.

The previous prime is 400651321529. The next prime is 400651321579. The reversal of 400651321572 is 275123156004.

400651321572 is a `hidden beast` number, since 4 + 0 + 0 + 6 + 51 + 32 + 1 + 572 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 842973156 + 399808348416 = 29034^2 + 632304^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (400651321579) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 19299054 + ... + 19319802.

It is an arithmetic number, because the mean of its divisors is an integer number (8880773825).

Almost surely, 2^400651321572 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 400651321572, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (532846429500).

400651321572 is an abundant number, since it is smaller than the sum of its proper divisors (665041537428).

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

400651321572 is a wasteful number, since it uses less digits than its factorization.

400651321572 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21803 (or 21792 counting only the distinct ones).

The product of its (nonzero) digits is 50400, while the sum is 36.

Adding to 400651321572 its reverse (275123156004), we get a palindrome (675774477576).

The spelling of 400651321572 in words is "four hundred billion, six hundred fifty-one million, three hundred twenty-one thousand, five hundred seventy-two".