1553120381 has 2 divisors, whose sum is σ = 1553120382. Its totient is φ = 1553120380.

The previous prime is 1553120351. The next prime is 1553120389. The reversal of 1553120381 is 1830213551.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 978751225 + 574369156 = 31285^2 + 23966^2 .

It is a cyclic number.

It is not a de Polignac number, because 1553120381 - 2²² = 1548926077 is a prime.

It is a super-2 number, since 2×1553120381² = 4824365835755170322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1553120389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 776560190 + 776560191.

It is an arithmetic number, because the mean of its divisors is an integer number (776560191).

Almost surely, 2^1553120381 is an apocalyptic number.

It is an amenable number.

1553120381 is a deficient number, since it is larger than the sum of its proper divisors (1).

1553120381 is an equidigital number, since it uses as much as digits as its factorization.

1553120381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3600, while the sum is 29.

The square root of 1553120381 is about 39409.6483237291. The cubic root of 1553120381 is about 1158.0706088256.

The spelling of 1553120381 in words is "one billion, five hundred fifty-three million, one hundred twenty thousand, three hundred eighty-one".