1220351557 has 2 divisors, whose sum is σ = 1220351558. Its totient is φ = 1220351556.

The previous prime is 1220351537. The next prime is 1220351603. The reversal of 1220351557 is 7551530221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1166973921 + 53377636 = 34161^2 + 7306^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1220351557 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1220351507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610175778 + 610175779.

It is an arithmetic number, because the mean of its divisors is an integer number (610175779).

Almost surely, 2^1220351557 is an apocalyptic number.

It is an amenable number.

1220351557 is a deficient number, since it is larger than the sum of its proper divisors (1).

1220351557 is an equidigital number, since it uses as much as digits as its factorization.

1220351557 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10500, while the sum is 31.

The square root of 1220351557 is about 34933.5305544687. The cubic root of 1220351557 is about 1068.6323566597.

Adding to 1220351557 its reverse (7551530221), we get a palindrome (8771881778).

The spelling of 1220351557 in words is "one billion, two hundred twenty million, three hundred fifty-one thousand, five hundred fifty-seven".