1621212077 has 2 divisors, whose sum is σ = 1621212078. Its totient is φ = 1621212076.

The previous prime is 1621212059. The next prime is 1621212079. The reversal of 1621212077 is 7702121261.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1245666436 + 375545641 = 35294^2 + 19379^2 .

It is a cyclic number.

It is not a de Polignac number, because 1621212077 - 2⁸ = 1621211821 is a prime.

It is a super-2 number, since 2×1621212077² = 5256657197221307858, which contains 22 as substring.

Together with 1621212079, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1621212079) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 810606038 + 810606039.

It is an arithmetic number, because the mean of its divisors is an integer number (810606039).

Almost surely, 2^1621212077 is an apocalyptic number.

It is an amenable number.

1621212077 is a deficient number, since it is larger than the sum of its proper divisors (1).

1621212077 is an equidigital number, since it uses as much as digits as its factorization.

1621212077 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2352, while the sum is 29.

The square root of 1621212077 is about 40264.2779272148. The cubic root of 1621212077 is about 1174.7531280353.

The spelling of 1621212077 in words is "one billion, six hundred twenty-one million, two hundred twelve thousand, seventy-seven".