193992021 has 6 divisors (see below), whose sum is σ = 280210710. Its totient is φ = 129328008.

The previous prime is 193991989. The next prime is 193992023. The reversal of 193992021 is 120299391.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 193515921 + 476100 = 13911^2 + 690^2 .

It is not a de Polignac number, because 193992021 - 2⁵ = 193991989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (193992023) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 10777326 + ... + 10777343.

It is an arithmetic number, because the mean of its divisors is an integer number (46701785).

Almost surely, 2^193992021 is an apocalyptic number.

It is an amenable number.

193992021 is a deficient number, since it is larger than the sum of its proper divisors (86218689).

193992021 is a wasteful number, since it uses less digits than its factorization.

193992021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21554675 (or 21554672 counting only the distinct ones).

The product of its (nonzero) digits is 8748, while the sum is 36.

The square root of 193992021 is about 13928.1018448315. The cubic root of 193992021 is about 578.8881006516. Note that the first 3 decimals are identical.

The spelling of 193992021 in words is "one hundred ninety-three million, nine hundred ninety-two thousand, twenty-one".