21221021120977 has 2 divisors, whose sum is σ = 21221021120978. Its totient is φ = 21221021120976.

The previous prime is 21221021120951. The next prime is 21221021121059. The reversal of 21221021120977 is 77902112012212.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15225986398401 + 5995034722576 = 3902049^2 + 2448476^2 .

It is a cyclic number.

It is not a de Polignac number, because 21221021120977 - 2³¹ = 21218873637329 is a prime.

It is not a weakly prime, because it can be changed into another prime (21221021121977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610510560488 + 10610510560489.

It is an arithmetic number, because the mean of its divisors is an integer number (10610510560489).

Almost surely, 2^{21221021120977} is an apocalyptic number.

It is an amenable number.

21221021120977 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221021120977 is an equidigital number, since it uses as much as digits as its factorization.

21221021120977 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14112, while the sum is 37.

The spelling of 21221021120977 in words is "twenty-one trillion, two hundred twenty-one billion, twenty-one million, one hundred twenty thousand, nine hundred seventy-seven".