190161821 has 2 divisors, whose sum is σ = 190161822. Its totient is φ = 190161820.

The previous prime is 190161757. The next prime is 190161841. The reversal of 190161821 is 128161091.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 188073796 + 2088025 = 13714^2 + 1445^2 .

It is a cyclic number.

It is not a de Polignac number, because 190161821 - 2⁶ = 190161757 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (190161841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95080910 + 95080911.

It is an arithmetic number, because the mean of its divisors is an integer number (95080911).

Almost surely, 2^190161821 is an apocalyptic number.

It is an amenable number.

190161821 is a deficient number, since it is larger than the sum of its proper divisors (1).

190161821 is an equidigital number, since it uses as much as digits as its factorization.

190161821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 29.

The square root of 190161821 is about 13789.9173674101. The cubic root of 190161821 is about 575.0528707528.

The spelling of 190161821 in words is "one hundred ninety million, one hundred sixty-one thousand, eight hundred twenty-one".