1621428277 has 12 divisors (see below), whose sum is σ = 1889453100. Its totient is φ = 1387362816.

The previous prime is 1621428257. The next prime is 1621428283. The reversal of 1621428277 is 7728241261.

It can be written as a sum of positive squares in 2 ways, for example, as 1385775076 + 235653201 = 37226^2 + 15351^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1621428277 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1621428257) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 402 + ... + 56947.

It is an arithmetic number, because the mean of its divisors is an integer number (157454425).

Almost surely, 2^1621428277 is an apocalyptic number.

It is an amenable number.

1621428277 is a deficient number, since it is larger than the sum of its proper divisors (268024823).

1621428277 is an equidigital number, since it uses as much as digits as its factorization.

1621428277 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57940 (or 57933 counting only the distinct ones).

The product of its digits is 75264, while the sum is 40.

The square root of 1621428277 is about 40266.9625996300. The cubic root of 1621428277 is about 1174.8053462369.

The spelling of 1621428277 in words is "one billion, six hundred twenty-one million, four hundred twenty-eight thousand, two hundred seventy-seven".