400030521 has 32 divisors (see below), whose sum is σ = 591349248. Its totient is φ = 238525440.

The previous prime is 400030511. The next prime is 400030529. The reversal of 400030521 is 125030004.

It is not a de Polignac number, because 400030521 - 2¹⁵ = 399997753 is a prime.

It is a super-3 number, since 3×400030521³ (a number of 27 digits) contains 333 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 400030521.

It is not an unprimeable number, because it can be changed into a prime (400030529) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 681190 + ... + 681776.

It is an arithmetic number, because the mean of its divisors is an integer number (18479664).

Almost surely, 2^400030521 is an apocalyptic number.

It is an amenable number.

400030521 is a deficient number, since it is larger than the sum of its proper divisors (191318727).

400030521 is a wasteful number, since it uses less digits than its factorization.

400030521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 901.

The product of its (nonzero) digits is 120, while the sum is 15.

The square root of 400030521 is about 20000.7630104454. The cubic root of 400030521 is about 736.8250393057.

Adding to 400030521 its reverse (125030004), we get a palindrome (525060525).

The spelling of 400030521 in words is "four hundred million, thirty thousand, five hundred twenty-one".