1620421251 has 16 divisors (see below), whose sum is σ = 2277930240. Its totient is φ = 1021779360.

The previous prime is 1620421247. The next prime is 1620421261. The reversal of 1620421251 is 1521240261.

It is not a de Polignac number, because 1620421251 - 2² = 1620421247 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1620421211) 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 15 ways as a sum of consecutive naturals, for example, 13441 + ... + 58493.

It is an arithmetic number, because the mean of its divisors is an integer number (142370640).

Almost surely, 2^1620421251 is an apocalyptic number.

1620421251 is a deficient number, since it is larger than the sum of its proper divisors (657508989).

1620421251 is a wasteful number, since it uses less digits than its factorization.

1620421251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45706.

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 1620421251 is about 40254.4562874721. The cubic root of 1620421251 is about 1174.5620824115.

The spelling of 1620421251 in words is "one billion, six hundred twenty million, four hundred twenty-one thousand, two hundred fifty-one".