406720989 has 12 divisors (see below), whose sum is σ = 587749500. Its totient is φ = 271025664.

The previous prime is 406720981. The next prime is 406720991. The reversal of 406720989 is 989027604.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 331604100 + 75116889 = 18210^2 + 8667^2 .

It is not a de Polignac number, because 406720989 - 2³ = 406720981 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (406720981) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14077 + ... + 31805.

It is an arithmetic number, because the mean of its divisors is an integer number (48979125).

Almost surely, 2^406720989 is an apocalyptic number.

It is an amenable number.

406720989 is a deficient number, since it is larger than the sum of its proper divisors (181028511).

406720989 is a wasteful number, since it uses less digits than its factorization.

406720989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20284 (or 20281 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The square root of 406720989 is about 20167.3247854047. The cubic root of 406720989 is about 740.9101225766.

The spelling of 406720989 in words is "four hundred six million, seven hundred twenty thousand, nine hundred eighty-nine".