400020705 has 24 divisors (see below), whose sum is σ = 792422592. Its totient is φ = 182866464.

The previous prime is 400020697. The next prime is 400020721. The reversal of 400020705 is 507020004.

It is a happy number.

It is not a de Polignac number, because 400020705 - 2³ = 400020697 is a prime.

It is a super-3 number, since 3×400020705³ (a number of 27 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 634639 + ... + 635268.

It is an arithmetic number, because the mean of its divisors is an integer number (33017608).

Almost surely, 2^400020705 is an apocalyptic number.

400020705 is a gapful number since it is divisible by the number (45) formed by its first and last digit.

It is an amenable number.

400020705 is a deficient number, since it is larger than the sum of its proper divisors (392401887).

400020705 is a wasteful number, since it uses less digits than its factorization.

400020705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1269925 (or 1269922 counting only the distinct ones).

The product of its (nonzero) digits is 280, while the sum is 18.

The square root of 400020705 is about 20000.5176183018. The cubic root of 400020705 is about 736.8190124874.

Adding to 400020705 its reverse (507020004), we get a palindrome (907040709).

The spelling of 400020705 in words is "four hundred million, twenty thousand, seven hundred five".