20278641 has 16 divisors (see below), whose sum is σ = 27961920. Its totient is φ = 13063680.

The previous prime is 20278631. The next prime is 20278649. The reversal of 20278641 is 14687202.

It is not a de Polignac number, because 20278641 - 2⁷ = 20278513 is a prime.

It is a super-2 number, since 2×20278641² = 822446561613762, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20278599 and 20278608.

It is not an unprimeable number, because it can be changed into a prime (20278649) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13170 + ... + 14628.

It is an arithmetic number, because the mean of its divisors is an integer number (1747620).

Almost surely, 2^20278641 is an apocalyptic number.

It is an amenable number.

20278641 is a deficient number, since it is larger than the sum of its proper divisors (7683279).

20278641 is a wasteful number, since it uses less digits than its factorization.

20278641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1616.

The product of its (nonzero) digits is 5376, while the sum is 30.

The square root of 20278641 is about 4503.1812088789. The cubic root of 20278641 is about 272.6965324646.

The spelling of 20278641 in words is "twenty million, two hundred seventy-eight thousand, six hundred forty-one".