157821473 has 2 divisors, whose sum is σ = 157821474. Its totient is φ = 157821472.

The previous prime is 157821463. The next prime is 157821479. The reversal of 157821473 is 374128751.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 151979584 + 5841889 = 12328^2 + 2417^2 .

It is an emirp because it is prime and its reverse (374128751) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 157821473 - 2¹² = 157817377 is a prime.

It is not a weakly prime, because it can be changed into another prime (157821479) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78910736 + 78910737.

It is an arithmetic number, because the mean of its divisors is an integer number (78910737).

Almost surely, 2^157821473 is an apocalyptic number.

It is an amenable number.

157821473 is a deficient number, since it is larger than the sum of its proper divisors (1).

157821473 is an equidigital number, since it uses as much as digits as its factorization.

157821473 is an evil number, because the sum of its binary digits is even.

The product of its digits is 47040, while the sum is 38.

The square root of 157821473 is about 12562.7016600730. The cubic root of 157821473 is about 540.4083251375.

The spelling of 157821473 in words is "one hundred fifty-seven million, eight hundred twenty-one thousand, four hundred seventy-three".