190451821 has 16 divisors (see below), whose sum is σ = 222469888. Its totient is φ = 159667200.

The previous prime is 190451803. The next prime is 190451827. The reversal of 190451821 is 128154091.

It is a happy number.

It is not a de Polignac number, because 190451821 - 2¹⁹ = 189927533 is a prime.

It is a super-2 number, since 2×190451821² = 72543792244432082, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (190451827) 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, 81256 + ... + 83566.

It is an arithmetic number, because the mean of its divisors is an integer number (13904368).

Almost surely, 2^190451821 is an apocalyptic number.

It is an amenable number.

190451821 is a deficient number, since it is larger than the sum of its proper divisors (32018067).

190451821 is a wasteful number, since it uses less digits than its factorization.

190451821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2572.

The product of its (nonzero) digits is 2880, while the sum is 31.

The square root of 190451821 is about 13800.4282904553. The cubic root of 190451821 is about 575.3450440714.

The spelling of 190451821 in words is "one hundred ninety million, four hundred fifty-one thousand, eight hundred twenty-one".