400749 has 4 divisors (see below), whose sum is σ = 534336. Its totient is φ = 267164.

The previous prime is 400739. The next prime is 400753. The reversal of 400749 is 947004.

400749 = 207² + 208² + ... + 215².

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 a cyclic number.

It is not a de Polignac number, because 400749 - 2⁹ = 400237 is a prime.

It is a super-2 number, since 2×400749² = 321199522002, which contains 22 as substring.

It is a D-number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400739) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66789 + ... + 66794.

It is an arithmetic number, because the mean of its divisors is an integer number (133584).

2⁴⁰⁰⁷⁴⁹ is an apocalyptic number.

It is an amenable number.

400749 is a deficient number, since it is larger than the sum of its proper divisors (133587).

400749 is a wasteful number, since it uses less digits than its factorization.

400749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133586.

The product of its (nonzero) digits is 1008, while the sum is 24.

The square root of 400749 is about 633.0473915909. The cubic root of 400749 is about 73.7265902910.

The spelling of 400749 in words is "four hundred thousand, seven hundred forty-nine".