921615481 has 2 divisors, whose sum is σ = 921615482. Its totient is φ = 921615480.

The previous prime is 921615479. The next prime is 921615521. The reversal of 921615481 is 184516129.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 847741456 + 73874025 = 29116^2 + 8595^2 .

It is a cyclic number.

It is not a de Polignac number, because 921615481 - 2¹ = 921615479 is a prime.

It is a super-2 number, since 2×921615481² = 1698750189637722722, which contains 22 as substring.

Together with 921615479, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 921615481.

It is not a weakly prime, because it can be changed into another prime (921615421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 460807740 + 460807741.

It is an arithmetic number, because the mean of its divisors is an integer number (460807741).

Almost surely, 2^921615481 is an apocalyptic number.

It is an amenable number.

921615481 is a deficient number, since it is larger than the sum of its proper divisors (1).

921615481 is an equidigital number, since it uses as much as digits as its factorization.

921615481 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17280, while the sum is 37.

The square root of 921615481 is about 30358.1205116522. The cubic root of 921615481 is about 973.1577682525.

The spelling of 921615481 in words is "nine hundred twenty-one million, six hundred fifteen thousand, four hundred eighty-one".