1622155921 has 2 divisors, whose sum is σ = 1622155922. Its totient is φ = 1622155920.

The previous prime is 1622155907. The next prime is 1622155943. The reversal of 1622155921 is 1295512261.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1010286225 + 611869696 = 31785^2 + 24736^2 .

It is a cyclic number.

It is not a de Polignac number, because 1622155921 - 2¹⁹ = 1621631633 is a prime.

It is not a weakly prime, because it can be changed into another prime (1622155021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 811077960 + 811077961.

It is an arithmetic number, because the mean of its divisors is an integer number (811077961).

Almost surely, 2^1622155921 is an apocalyptic number.

It is an amenable number.

1622155921 is a deficient number, since it is larger than the sum of its proper divisors (1).

1622155921 is an equidigital number, since it uses as much as digits as its factorization.

1622155921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10800, while the sum is 34.

The square root of 1622155921 is about 40275.9968343429. The cubic root of 1622155921 is about 1174.9810580317.

It can be divided in two parts, 1622155 and 921, that added together give a square (1623076 = 1274²).

The spelling of 1622155921 in words is "one billion, six hundred twenty-two million, one hundred fifty-five thousand, nine hundred twenty-one".