400000051 has 4 divisors (see below), whose sum is σ = 436363704. Its totient is φ = 363636400.

The previous prime is 400000049. The next prime is 400000067. The reversal of 400000051 is 150000004.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 400000051 - 2¹ = 400000049 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 399999983 and 400000037.

It is not an unprimeable number, because it can be changed into a prime (400000091) 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, 18181810 + ... + 18181831.

It is an arithmetic number, because the mean of its divisors is an integer number (109090926).

Almost surely, 2^400000051 is an apocalyptic number.

400000051 is a deficient number, since it is larger than the sum of its proper divisors (36363653).

400000051 is a wasteful number, since it uses less digits than its factorization.

400000051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36363652.

The product of its (nonzero) digits is 20, while the sum is 10.

The square root of 400000051 is about 20000.0012750000. The cubic root of 400000051 is about 736.8063310423.

Adding to 400000051 its reverse (150000004), we get a palindrome (550000055).

The spelling of 400000051 in words is "four hundred million, fifty-one", and thus it is an aban number.