1621442051 has 4 divisors (see below), whose sum is σ = 1627425504. Its totient is φ = 1615458600.

The previous prime is 1621442027. The next prime is 1621442093. The reversal of 1621442051 is 1502441261.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1621442051 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1621442051.

It is not an unprimeable number, because it can be changed into a prime (1621442551) 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 3 ways as a sum of consecutive naturals, for example, 2991320 + ... + 2991861.

It is an arithmetic number, because the mean of its divisors is an integer number (406856376).

Almost surely, 2^1621442051 is an apocalyptic number.

1621442051 is a deficient number, since it is larger than the sum of its proper divisors (5983453).

1621442051 is an equidigital number, since it uses as much as digits as its factorization.

1621442051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5983452.

The product of its (nonzero) digits is 1920, while the sum is 26.

The square root of 1621442051 is about 40267.1336327780. The cubic root of 1621442051 is about 1174.8086728766.

The spelling of 1621442051 in words is "one billion, six hundred twenty-one million, four hundred forty-two thousand, fifty-one".