400099521 has 4 divisors (see below), whose sum is σ = 533466032. Its totient is φ = 266733012.

The previous prime is 400099519. The next prime is 400099603. The reversal of 400099521 is 125990004.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 400099521 - 2¹ = 400099519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (400091521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66683251 + ... + 66683256.

It is an arithmetic number, because the mean of its divisors is an integer number (133366508).

Almost surely, 2^400099521 is an apocalyptic number.

It is an amenable number.

400099521 is a deficient number, since it is larger than the sum of its proper divisors (133366511).

400099521 is a wasteful number, since it uses less digits than its factorization.

400099521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133366510.

The product of its (nonzero) digits is 3240, while the sum is 30.

The square root of 400099521 is about 20002.4878702625. The cubic root of 400099521 is about 736.8674010774.

The spelling of 400099521 in words is "four hundred million, ninety-nine thousand, five hundred twenty-one".