1021357861 has 2 divisors, whose sum is σ = 1021357862. Its totient is φ = 1021357860.

The previous prime is 1021357829. The next prime is 1021357871. The reversal of 1021357861 is 1687531201.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 757295361 + 264062500 = 27519^2 + 16250^2 .

It is a cyclic number.

It is not a de Polignac number, because 1021357861 - 2⁵ = 1021357829 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1021357871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510678930 + 510678931.

It is an arithmetic number, because the mean of its divisors is an integer number (510678931).

Almost surely, 2^1021357861 is an apocalyptic number.

It is an amenable number.

1021357861 is a deficient number, since it is larger than the sum of its proper divisors (1).

1021357861 is an equidigital number, since it uses as much as digits as its factorization.

1021357861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10080, while the sum is 34.

The square root of 1021357861 is about 31958.6899136995. The cubic root of 1021357861 is about 1007.0691957144.

The spelling of 1021357861 in words is "one billion, twenty-one million, three hundred fifty-seven thousand, eight hundred sixty-one".