1091578402 has 4 divisors (see below), whose sum is σ = 1637367606. Its totient is φ = 545789200.

The previous prime is 1091578399. The next prime is 1091578441. The reversal of 1091578402 is 2048751901.

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

It can be written as a sum of positive squares in only one way, i.e., 1091046961 + 531441 = 33031^2 + 729^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 272894599 + ... + 272894602.

Almost surely, 2^1091578402 is an apocalyptic number.

1091578402 is a deficient number, since it is larger than the sum of its proper divisors (545789204).

1091578402 is an equidigital number, since it uses as much as digits as its factorization.

1091578402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 545789203.

The product of its (nonzero) digits is 20160, while the sum is 37.

The square root of 1091578402 is about 33039.0435999591. The cubic root of 1091578402 is about 1029.6389855541.

The spelling of 1091578402 in words is "one billion, ninety-one million, five hundred seventy-eight thousand, four hundred two".