1051856821 has 2 divisors, whose sum is σ = 1051856822. Its totient is φ = 1051856820.

The previous prime is 1051856803. The next prime is 1051856833. The reversal of 1051856821 is 1286581501.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1047234321 + 4622500 = 32361^2 + 2150^2 .

It is a cyclic number.

It is not a de Polignac number, because 1051856821 - 2¹⁷ = 1051725749 is a prime.

It is a super-2 number, since 2×1051856821² = 2212805543768452082, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1051851821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 525928410 + 525928411.

It is an arithmetic number, because the mean of its divisors is an integer number (525928411).

Almost surely, 2^1051856821 is an apocalyptic number.

It is an amenable number.

1051856821 is a deficient number, since it is larger than the sum of its proper divisors (1).

1051856821 is an equidigital number, since it uses as much as digits as its factorization.

1051856821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19200, while the sum is 37.

The square root of 1051856821 is about 32432.3422065074. The cubic root of 1051856821 is about 1016.9951360880.

The spelling of 1051856821 in words is "one billion, fifty-one million, eight hundred fifty-six thousand, eight hundred twenty-one".