102121551 has 12 divisors (see below), whose sum is σ = 168581712. Its totient is φ = 58355136.

The previous prime is 102121531. The next prime is 102121577. The reversal of 102121551 is 155121201.

102121551 is a `hidden beast` number, since 102 + 12 + 1 + 551 = 666.

It is not a de Polignac number, because 102121551 - 2⁵ = 102121519 is a prime.

It is a super-2 number, since 2×102121551² = 20857622357291202, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102121531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 810426 + ... + 810551.

It is an arithmetic number, because the mean of its divisors is an integer number (14048476).

Almost surely, 2^102121551 is an apocalyptic number.

102121551 is a deficient number, since it is larger than the sum of its proper divisors (66460161).

102121551 is a wasteful number, since it uses less digits than its factorization.

102121551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1620990 (or 1620987 counting only the distinct ones).

The product of its (nonzero) digits is 100, while the sum is 18.

The square root of 102121551 is about 10105.5208178500. The cubic root of 102121551 is about 467.4183959675.

Adding to 102121551 its reverse (155121201), we get a palindrome (257242752).

The spelling of 102121551 in words is "one hundred two million, one hundred twenty-one thousand, five hundred fifty-one".