400280049 has 81 divisors (see below), whose sum is σ = 686144043. Its totient is φ = 233361648.

The previous prime is 400280047. The next prime is 400280057. The reversal of 400280049 is 940082004.

The square root of 400280049 is 20007.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 59213025 + 341067024 = 7695^2 + 18468^2 .

It is a tau number, because it is divible by the number of its divisors (81).

It is not a de Polignac number, because 400280049 - 2¹ = 400280047 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (400280047) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 21067362 + ... + 21067380.

Almost surely, 2^400280049 is an apocalyptic number.

400280049 is the 20007-th square number.

400280049 is the 10004-th centered octagonal number.

It is an amenable number.

400280049 is a deficient number, since it is larger than the sum of its proper divisors (285863994).

400280049 is an frugal number, since it uses more digits than its factorization.

400280049 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88 (or 35 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The cubic root of 400280049 is about 736.9782111708.

Multiplying 400280049 by its product of nonzero digits (2304), we get a square (922245232896 = 960336²).

The spelling of 400280049 in words is "four hundred million, two hundred eighty thousand, forty-nine".