646621231 has 8 divisors (see below), whose sum is σ = 689657760. Its totient is φ = 604140288.

The previous prime is 646621201. The next prime is 646621249. The reversal of 646621231 is 132126646.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 646621231 - 2¹⁹ = 646096943 is a prime.

It is a super-2 number, since 2×646621231² = 836238032759910722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 646621193 and 646621202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646621201) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 136491 + ... + 141148.

It is an arithmetic number, because the mean of its divisors is an integer number (86207220).

Almost surely, 2^646621231 is an apocalyptic number.

646621231 is a deficient number, since it is larger than the sum of its proper divisors (43036529).

646621231 is a wasteful number, since it uses less digits than its factorization.

646621231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 277793.

The product of its digits is 10368, while the sum is 31.

The square root of 646621231 is about 25428.7481209752. The cubic root of 646621231 is about 864.7355628578.

Adding to 646621231 its reverse (132126646), we get a palindrome (778747877).

The spelling of 646621231 in words is "six hundred forty-six million, six hundred twenty-one thousand, two hundred thirty-one".