19866521354 has 16 divisors (see below), whose sum is σ = 31340279808. Its totient is φ = 9426562992.

The previous prime is 19866521347. The next prime is 19866521371. The reversal of 19866521354 is 45312566891.

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, 1694477 + ... + 1706160.

It is an arithmetic number, because the mean of its divisors is an integer number (1958767488).

Almost surely, 2^19866521354 is an apocalyptic number.

19866521354 is a deficient number, since it is larger than the sum of its proper divisors (11473758454).

19866521354 is a wasteful number, since it uses less digits than its factorization.

19866521354 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3400789.

The product of its digits is 1555200, while the sum is 50.

The spelling of 19866521354 in words is "nineteen billion, eight hundred sixty-six million, five hundred twenty-one thousand, three hundred fifty-four".