115451821 has 2 divisors, whose sum is σ = 115451822. Its totient is φ = 115451820.

The previous prime is 115451767. The next prime is 115451851. The reversal of 115451821 is 128154511.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 88266025 + 27185796 = 9395^2 + 5214^2 .

It is a cyclic number.

It is not a de Polignac number, because 115451821 - 2²¹ = 113354669 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 115451821.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (115451851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 57725910 + 57725911.

It is an arithmetic number, because the mean of its divisors is an integer number (57725911).

Almost surely, 2^115451821 is an apocalyptic number.

It is an amenable number.

115451821 is a deficient number, since it is larger than the sum of its proper divisors (1).

115451821 is an equidigital number, since it uses as much as digits as its factorization.

115451821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1600, while the sum is 28.

The square root of 115451821 is about 10744.8509063644. The cubic root of 115451821 is about 486.9304447210.

It can be divided in two parts, 11545 and 1821, that added together give a triangular number (13366 = T₁₆₃).

The spelling of 115451821 in words is "one hundred fifteen million, four hundred fifty-one thousand, eight hundred twenty-one".