290821428 has 42 divisors (see below), whose sum is σ = 763064834. Its totient is φ = 96939504.

The previous prime is 290821417. The next prime is 290821439. The reversal of 290821428 is 824128092.

It is an interprime number because it is at equal distance from previous prime (290821417) and next prime (290821439).

It can be written as a sum of positive squares in only one way, i.e., 285677604 + 5143824 = 16902^2 + 2268^2 .

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 290821392 and 290821401.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 46951 + ... + 52782.

Almost surely, 2^290821428 is an apocalyptic number.

It is an amenable number.

290821428 is an abundant number, since it is smaller than the sum of its proper divisors (472243406).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

290821428 is an equidigital number, since it uses as much as digits as its factorization.

290821428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99755 (or 99738 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 290821428 is about 17053.4872680047. The cubic root of 290821428 is about 662.5349618668.

It can be divided in two parts, 2908 and 21428, that added together give a square (24336 = 156²).

The spelling of 290821428 in words is "two hundred ninety million, eight hundred twenty-one thousand, four hundred twenty-eight".