1972721473 has 2 divisors, whose sum is σ = 1972721474. Its totient is φ = 1972721472.

The previous prime is 1972721467. The next prime is 1972721551. The reversal of 1972721473 is 3741272791.

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., 1709243649 + 263477824 = 41343^2 + 16232^2 .

It is a cyclic number.

It is not a de Polignac number, because 1972721473 - 2²⁹ = 1435850561 is a prime.

It is not a weakly prime, because it can be changed into another prime (1972721573) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 986360736 + 986360737.

It is an arithmetic number, because the mean of its divisors is an integer number (986360737).

Almost surely, 2^1972721473 is an apocalyptic number.

It is an amenable number.

1972721473 is a deficient number, since it is larger than the sum of its proper divisors (1).

1972721473 is an equidigital number, since it uses as much as digits as its factorization.

1972721473 is an evil number, because the sum of its binary digits is even.

The product of its digits is 148176, while the sum is 43.

The square root of 1972721473 is about 44415.3292569131. The cubic root of 1972721473 is about 1254.1666765199.

The spelling of 1972721473 in words is "one billion, nine hundred seventy-two million, seven hundred twenty-one thousand, four hundred seventy-three".