20980621901 has 2 divisors, whose sum is σ = 20980621902. Its totient is φ = 20980621900.

The previous prime is 20980621861. The next prime is 20980621951. The reversal of 20980621901 is 10912608902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20930566276 + 50055625 = 144674^2 + 7075^2 .

It is a cyclic number.

It is not a de Polignac number, because 20980621901 - 2²² = 20976427597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20980621951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10490310950 + 10490310951.

It is an arithmetic number, because the mean of its divisors is an integer number (10490310951).

Almost surely, 2^20980621901 is an apocalyptic number.

It is an amenable number.

20980621901 is a deficient number, since it is larger than the sum of its proper divisors (1).

20980621901 is an equidigital number, since it uses as much as digits as its factorization.

20980621901 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15552, while the sum is 38.

The spelling of 20980621901 in words is "twenty billion, nine hundred eighty million, six hundred twenty-one thousand, nine hundred one".