1021451155 has 4 divisors (see below), whose sum is σ = 1225741392. Its totient is φ = 817160920.

The previous prime is 1021451117. The next prime is 1021451159. The reversal of 1021451155 is 5511541201.

It is a semiprime because it is the product of two primes.

It is a de Polignac number, because none of the positive numbers 2^k-1021451155 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1021451159) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 102145111 + ... + 102145120.

It is an arithmetic number, because the mean of its divisors is an integer number (306435348).

Almost surely, 2^1021451155 is an apocalyptic number.

1021451155 is a deficient number, since it is larger than the sum of its proper divisors (204290237).

1021451155 is an equidigital number, since it uses as much as digits as its factorization.

1021451155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204290236.

The product of its (nonzero) digits is 1000, while the sum is 25.

The square root of 1021451155 is about 31960.1494833801. The cubic root of 1021451155 is about 1007.0998577238.

Adding to 1021451155 its reverse (5511541201), we get a palindrome (6532992356).

The spelling of 1021451155 in words is "one billion, twenty-one million, four hundred fifty-one thousand, one hundred fifty-five".