641121949 has 8 divisors (see below), whose sum is σ = 694526840. Its totient is φ = 591802848.

The previous prime is 641121947. The next prime is 641121979. The reversal of 641121949 is 949121146.

It can be written as a sum of positive squares in 4 ways, for example, as 42341049 + 598780900 = 6507^2 + 24470^2 .

It is not a de Polignac number, because 641121949 - 2¹ = 641121947 is a prime.

It is a super-2 number, since 2×641121949² = 822074706979117202, 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 (641121947) 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, 143712 + ... + 148105.

It is an arithmetic number, because the mean of its divisors is an integer number (86815855).

Almost surely, 2^641121949 is an apocalyptic number.

It is an amenable number.

641121949 is a deficient number, since it is larger than the sum of its proper divisors (53404891).

641121949 is an equidigital number, since it uses as much as digits as its factorization.

641121949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 291856 (or 291830 counting only the distinct ones).

The product of its digits is 15552, while the sum is 37.

The square root of 641121949 is about 25320.3860357618. The cubic root of 641121949 is about 862.2771582530.

The spelling of 641121949 in words is "six hundred forty-one million, one hundred twenty-one thousand, nine hundred forty-nine".