421791781 has 4 divisors (see below), whose sum is σ = 421898112. Its totient is φ = 421685452.

The previous prime is 421791751. The next prime is 421791787. The reversal of 421791781 is 187197124.

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.

It is a cyclic number.

It is not a de Polignac number, because 421791781 - 2⁷ = 421791653 is a prime.

It is a super-2 number, since 2×421791781² = 355816613038303922, 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 (421791787) 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, 46975 + ... + 55228.

It is an arithmetic number, because the mean of its divisors is an integer number (105474528).

Almost surely, 2^421791781 is an apocalyptic number.

It is an amenable number.

421791781 is a deficient number, since it is larger than the sum of its proper divisors (106331).

421791781 is a wasteful number, since it uses less digits than its factorization.

421791781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106330.

The product of its digits is 28224, while the sum is 40.

The square root of 421791781 is about 20537.5699877079. The cubic root of 421791781 is about 749.9506817941.

The spelling of 421791781 in words is "four hundred twenty-one million, seven hundred ninety-one thousand, seven hundred eighty-one".