20278461 has 16 divisors (see below), whose sum is σ = 30982784. Its totient is φ = 11556864.

The previous prime is 20278459. The next prime is 20278481. The reversal of 20278461 is 16487202.

It is not a de Polignac number, because 20278461 - 2¹ = 20278459 is a prime.

It is a super-2 number, since 2×20278461² = 822431961057042, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20278411) 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, 8541 + ... + 10653.

It is an arithmetic number, because the mean of its divisors is an integer number (1936424).

Almost surely, 2^20278461 is an apocalyptic number.

20278461 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20278461 is a deficient number, since it is larger than the sum of its proper divisors (10704323).

20278461 is a wasteful number, since it uses less digits than its factorization.

20278461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2580.

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

The square root of 20278461 is about 4503.1612229633. The cubic root of 20278461 is about 272.6957256136.

The spelling of 20278461 in words is "twenty million, two hundred seventy-eight thousand, four hundred sixty-one".