1281397642 has 16 divisors (see below), whose sum is σ = 2238129792. Its totient is φ = 538808400.

The previous prime is 1281397619. The next prime is 1281397651. The reversal of 1281397642 is 2467931821.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 862734 + ... + 864217.

It is an arithmetic number, because the mean of its divisors is an integer number (139883112).

Almost surely, 2^1281397642 is an apocalyptic number.

1281397642 is a deficient number, since it is larger than the sum of its proper divisors (956732150).

1281397642 is a wasteful number, since it uses less digits than its factorization.

1281397642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1727013.

The product of its digits is 145152, while the sum is 43.

The square root of 1281397642 is about 35796.6149516962. The cubic root of 1281397642 is about 1086.1620887299.

The spelling of 1281397642 in words is "one billion, two hundred eighty-one million, three hundred ninety-seven thousand, six hundred forty-two".