2091621842 has 18 divisors (see below), whose sum is σ = 3188196837. Its totient is φ = 1029156336.

The previous prime is 2091621823. The next prime is 2091621899. The reversal of 2091621842 is 2481261902.

It can be written as a sum of positive squares in 2 ways, for example, as 2082005641 + 9616201 = 45629^2 + 3101^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=32339.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 4721273 + ... + 4721715.

Almost surely, 2^2091621842 is an apocalyptic number.

2091621842 is a deficient number, since it is larger than the sum of its proper divisors (1096574995).

2091621842 is an frugal number, since it uses more digits than its factorization.

2091621842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1034 (or 518 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 35.

The square root of 2091621842 is about 45734.2523935835. The cubic root of 2091621842 is about 1278.8738960541.

The spelling of 2091621842 in words is "two billion, ninety-one million, six hundred twenty-one thousand, eight hundred forty-two".