21051691526740 has 48 divisors (see below), whose sum is σ = 50524465404672. Its totient is φ = 7217664846336.

The previous prime is 21051691526731. The next prime is 21051691526809. The reversal of 21051691526740 is 4762519615012.

It is a super-2 number, since 2×21051691526740² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19204332 + ... + 20270908.

It is an arithmetic number, because the mean of its divisors is an integer number (1052593029264).

Almost surely, 2^{21051691526740} is an apocalyptic number.

21051691526740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21051691526740 is an abundant number, since it is smaller than the sum of its proper divisors (29472773877932).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21051691526740 is a wasteful number, since it uses less digits than its factorization.

21051691526740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1207576 (or 1207574 counting only the distinct ones).

The product of its (nonzero) digits is 907200, while the sum is 49.

The spelling of 21051691526740 in words is "twenty-one trillion, fifty-one billion, six hundred ninety-one million, five hundred twenty-six thousand, seven hundred forty".