20278225 has 24 divisors (see below), whose sum is σ = 28882080. Its totient is φ = 13968000.

The previous prime is 20278201. The next prime is 20278253. The reversal of 20278225 is 52287202.

It is a de Polignac number, because none of the positive numbers 2^k-20278225 is a prime.

It is a super-2 number, since 2×20278225² = 822412818301250, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20278193 and 20278202.

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, 3285 + ... + 7165.

It is an arithmetic number, because the mean of its divisors is an integer number (1203420).

Almost surely, 2^20278225 is an apocalyptic number.

20278225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20278225 is a deficient number, since it is larger than the sum of its proper divisors (8603855).

20278225 is a wasteful number, since it uses less digits than its factorization.

20278225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3921 (or 3916 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 28.

The square root of 20278225 is about 4503.1350190728. The cubic root of 20278225 is about 272.6946677352.

It can be divided in two parts, 20278 and 225, that added together give a triangular number (20503 = T₂₀₂).

The spelling of 20278225 in words is "twenty million, two hundred seventy-eight thousand, two hundred twenty-five".