157221294409418 has 4 divisors (see below), whose sum is σ = 235831941614130. Its totient is φ = 78610647204708.

The previous prime is 157221294409411. The next prime is 157221294409447. The reversal of 157221294409418 is 814904492122751.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 156068477751169 + 1152816658249 = 12492737^2 + 1073693^2 .

It is a super-2 number, since 2×157221294409418² (a number of 29 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (157221294409411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39305323602353 + ... + 39305323602356.

Almost surely, 2^{157221294409418} is an apocalyptic number.

157221294409418 is a deficient number, since it is larger than the sum of its proper divisors (78610647204712).

157221294409418 is an equidigital number, since it uses as much as digits as its factorization.

157221294409418 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78610647204711.

The product of its (nonzero) digits is 11612160, while the sum is 59.

The spelling of 157221294409418 in words is "one hundred fifty-seven trillion, two hundred twenty-one billion, two hundred ninety-four million, four hundred nine thousand, four hundred eighteen".