20274781 has 4 divisors (see below), whose sum is σ = 20320992. Its totient is φ = 20228572.

The previous prime is 20274773. The next prime is 20274791. The reversal of 20274781 is 18747202.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18747202 = 2 ⋅9373601.

It is a cyclic number.

It is not a de Polignac number, because 20274781 - 2³ = 20274773 is a prime.

It is a super-2 number, since 2×20274781² = 822133489195922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20274791) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22441 + ... + 23326.

It is an arithmetic number, because the mean of its divisors is an integer number (5080248).

Almost surely, 2^20274781 is an apocalyptic number.

It is an amenable number.

20274781 is a deficient number, since it is larger than the sum of its proper divisors (46211).

20274781 is an equidigital number, since it uses as much as digits as its factorization.

20274781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46210.

The product of its (nonzero) digits is 6272, while the sum is 31.

The square root of 20274781 is about 4502.7526025755. The cubic root of 20274781 is about 272.6792289479.

The spelling of 20274781 in words is "twenty million, two hundred seventy-four thousand, seven hundred eighty-one".