634821919 has 16 divisors (see below), whose sum is σ = 689587200. Its totient is φ = 582585696.

The previous prime is 634821907. The next prime is 634821953. The reversal of 634821919 is 919128436.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 634821919 - 2¹³ = 634813727 is a prime.

It is a super-2 number, since 2×634821919² = 805997737685685122, 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 (634821989) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 105802 + ... + 111640.

It is an arithmetic number, because the mean of its divisors is an integer number (43099200).

Almost surely, 2^634821919 is an apocalyptic number.

634821919 is a deficient number, since it is larger than the sum of its proper divisors (54765281).

634821919 is a wasteful number, since it uses less digits than its factorization.

634821919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6054.

The product of its digits is 93312, while the sum is 43.

The square root of 634821919 is about 25195.6726244806. The cubic root of 634821919 is about 859.4434469145.

The spelling of 634821919 in words is "six hundred thirty-four million, eight hundred twenty-one thousand, nine hundred nineteen".