428640397 has 8 divisors (see below), whose sum is σ = 473587776. Its totient is φ = 385885632.

The previous prime is 428640391. The next prime is 428640409. The reversal of 428640397 is 793046824.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 428640397 - 2⁷ = 428640269 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (428640391) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 547743 + ... + 548524.

It is an arithmetic number, because the mean of its divisors is an integer number (59198472).

Almost surely, 2^428640397 is an apocalyptic number.

It is an amenable number.

428640397 is a deficient number, since it is larger than the sum of its proper divisors (44947379).

428640397 is a wasteful number, since it uses less digits than its factorization.

428640397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1096307.

The product of its (nonzero) digits is 290304, while the sum is 43.

The square root of 428640397 is about 20703.6324590638. The cubic root of 428640397 is about 753.9878822923.

The spelling of 428640397 in words is "four hundred twenty-eight million, six hundred forty thousand, three hundred ninety-seven".