1621212105 has 64 divisors (see below), whose sum is σ = 2699889408. Its totient is φ = 830361600.

The previous prime is 1621212097. The next prime is 1621212133. The reversal of 1621212105 is 5012121261.

It is not a de Polignac number, because 1621212105 - 2³ = 1621212097 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 11833597 + ... + 11833733.

It is an arithmetic number, because the mean of its divisors is an integer number (42185772).

Almost surely, 2^1621212105 is an apocalyptic number.

1621212105 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1621212105 is a deficient number, since it is larger than the sum of its proper divisors (1078677303).

1621212105 is a wasteful number, since it uses less digits than its factorization.

1621212105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 426.

The product of its (nonzero) digits is 240, while the sum is 21.

The square root of 1621212105 is about 40264.2782749176. The cubic root of 1621212105 is about 1174.7531347984.

Adding to 1621212105 its reverse (5012121261), we get a palindrome (6633333366).

The spelling of 1621212105 in words is "one billion, six hundred twenty-one million, two hundred twelve thousand, one hundred five".