1972095821 has 2 divisors, whose sum is σ = 1972095822. Its totient is φ = 1972095820.

The previous prime is 1972095793. The next prime is 1972095871. The reversal of 1972095821 is 1285902791.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1429671721 + 542424100 = 37811^2 + 23290^2 .

It is a cyclic number.

It is not a de Polignac number, because 1972095821 - 2⁶ = 1972095757 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1972095871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 986047910 + 986047911.

It is an arithmetic number, because the mean of its divisors is an integer number (986047911).

Almost surely, 2^1972095821 is an apocalyptic number.

It is an amenable number.

1972095821 is a deficient number, since it is larger than the sum of its proper divisors (1).

1972095821 is an equidigital number, since it uses as much as digits as its factorization.

1972095821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 90720, while the sum is 44.

The square root of 1972095821 is about 44408.2854994426. The cubic root of 1972095821 is about 1254.0340754629.

The spelling of 1972095821 in words is "one billion, nine hundred seventy-two million, ninety-five thousand, eight hundred twenty-one".