21020697907066 has 64 divisors (see below), whose sum is σ = 37731043123200. Its totient is φ = 8656638782400.

The previous prime is 21020697906953. The next prime is 21020697907093. The reversal of 21020697907066 is 66070979602012.

It is a junction number, because it is equal to n+sod(n) for n = 21020697906998 and 21020697907016.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9660375 + ... + 11634613.

It is an arithmetic number, because the mean of its divisors is an integer number (589547548800).

Almost surely, 2^{21020697907066} is an apocalyptic number.

21020697907066 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21020697907066 is a deficient number, since it is larger than the sum of its proper divisors (16710345216134).

21020697907066 is a wasteful number, since it uses less digits than its factorization.

21020697907066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1974955.

The product of its (nonzero) digits is 3429216, while the sum is 55.

The spelling of 21020697907066 in words is "twenty-one trillion, twenty billion, six hundred ninety-seven million, nine hundred seven thousand, sixty-six".