157221787 has 2 divisors, whose sum is σ = 157221788. Its totient is φ = 157221786.

The previous prime is 157221781. The next prime is 157221817. The reversal of 157221787 is 787122751.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-157221787 is a prime.

It is not a weakly prime, because it can be changed into another prime (157221781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78610893 + 78610894.

It is an arithmetic number, because the mean of its divisors is an integer number (78610894).

Almost surely, 2^157221787 is an apocalyptic number.

157221787 is a deficient number, since it is larger than the sum of its proper divisors (1).

157221787 is an equidigital number, since it uses as much as digits as its factorization.

157221787 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 54880, while the sum is 40.

The square root of 157221787 is about 12538.8112275447. The cubic root of 157221787 is about 539.7229797692.

The spelling of 157221787 in words is "one hundred fifty-seven million, two hundred twenty-one thousand, seven hundred eighty-seven".