21661246156454 has 8 divisors (see below), whose sum is σ = 32491925725800. Its totient is φ = 10830604247856.

The previous prime is 21661246156447. The next prime is 21661246156469. The reversal of 21661246156454 is 45465164216612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 21661246156396 and 21661246156405.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7930439 + ... + 10306034.

It is an arithmetic number, because the mean of its divisors is an integer number (4061490715725).

Almost surely, 2^{21661246156454} is an apocalyptic number.

21661246156454 is a deficient number, since it is larger than the sum of its proper divisors (10830679569346).

21661246156454 is a wasteful number, since it uses less digits than its factorization.

21661246156454 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18830374.

The product of its digits is 8294400, while the sum is 53.

The spelling of 21661246156454 in words is "twenty-one trillion, six hundred sixty-one billion, two hundred forty-six million, one hundred fifty-six thousand, four hundred fifty-four".