21553490642468 has 6 divisors (see below), whose sum is σ = 37718608624326. Its totient is φ = 10776745321232.

The previous prime is 21553490642429. The next prime is 21553490642527. The reversal of 21553490642468 is 86424609435512.

It can be written as a sum of positive squares in only one way, i.e., 15600856843264 + 5952633799204 = 3949792^2 + 2439802^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2694186330305 + ... + 2694186330312.

It is an arithmetic number, because the mean of its divisors is an integer number (6286434770721).

Almost surely, 2^{21553490642468} is an apocalyptic number.

It is an amenable number.

21553490642468 is a deficient number, since it is larger than the sum of its proper divisors (16165117981858).

21553490642468 is a wasteful number, since it uses less digits than its factorization.

21553490642468 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5388372660621 (or 5388372660619 counting only the distinct ones).

The product of its (nonzero) digits is 49766400, while the sum is 59.

The spelling of 21553490642468 in words is "twenty-one trillion, five hundred fifty-three billion, four hundred ninety million, six hundred forty-two thousand, four hundred sixty-eight".