20615428 has 12 divisors (see below), whose sum is σ = 36121932. Its totient is φ = 10294880.

The previous prime is 20615417. The next prime is 20615443. The reversal of 20615428 is 82451602.

It can be written as a sum of positive squares in 2 ways, for example, as 18249984 + 2365444 = 4272^2 + 1538^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20615396 and 20615405.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1026 + ... + 6502.

It is an arithmetic number, because the mean of its divisors is an integer number (3010161).

Almost surely, 2^20615428 is an apocalyptic number.

It is an amenable number.

20615428 is a deficient number, since it is larger than the sum of its proper divisors (15506504).

20615428 is a wasteful number, since it uses less digits than its factorization.

20615428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6422 (or 6420 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 28.

The square root of 20615428 is about 4540.4215663306. The cubic root of 20615428 is about 274.1978963552.

The spelling of 20615428 in words is "twenty million, six hundred fifteen thousand, four hundred twenty-eight".