1621772829 has 12 divisors (see below), whose sum is σ = 2423339100. Its totient is φ = 1043899584.

The previous prime is 1621772827. The next prime is 1621772833. The reversal of 1621772829 is 9282771261.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1290605625 + 331167204 = 35925^2 + 18198^2 .

It is not a de Polignac number, because 1621772829 - 2¹ = 1621772827 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1621772827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3106584 + ... + 3107105.

It is an arithmetic number, because the mean of its divisors is an integer number (201944925).

Almost surely, 2^1621772829 is an apocalyptic number.

It is an amenable number.

1621772829 is a deficient number, since it is larger than the sum of its proper divisors (801566271).

1621772829 is a wasteful number, since it uses less digits than its factorization.

1621772829 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6213724 (or 6213721 counting only the distinct ones).

The product of its digits is 169344, while the sum is 45.

The square root of 1621772829 is about 40271.2407184085. The cubic root of 1621772829 is about 1174.8885553575. Note that the first 3 decimals are identical.

The spelling of 1621772829 in words is "one billion, six hundred twenty-one million, seven hundred seventy-two thousand, eight hundred twenty-nine".