810456421 has 4 divisors (see below), whose sum is σ = 818480844. Its totient is φ = 802432000.

The previous prime is 810456407. The next prime is 810456433. The reversal of 810456421 is 124654018.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 124654018 = 2 ⋅62327009.

It can be written as a sum of positive squares in 2 ways, for example, as 527207521 + 283248900 = 22961^2 + 16830^2 .

It is a cyclic number.

It is not a de Polignac number, because 810456421 - 2²³ = 802067813 is a prime.

It is a super-2 number, since 2×810456421² = 1313679220680258482, 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 (810456401) 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, 4012060 + ... + 4012261.

It is an arithmetic number, because the mean of its divisors is an integer number (204620211).

Almost surely, 2^810456421 is an apocalyptic number.

It is an amenable number.

810456421 is a deficient number, since it is larger than the sum of its proper divisors (8024423).

810456421 is a wasteful number, since it uses less digits than its factorization.

810456421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8024422.

The product of its (nonzero) digits is 7680, while the sum is 31.

The square root of 810456421 is about 28468.5163118839. The cubic root of 810456421 is about 932.3448060914.

The spelling of 810456421 in words is "eight hundred ten million, four hundred fifty-six thousand, four hundred twenty-one".