121201551 has 48 divisors (see below), whose sum is σ = 197065440. Its totient is φ = 71331840.

The previous prime is 121201543. The next prime is 121201567. The reversal of 121201551 is 155102121.

It is not a de Polignac number, because 121201551 - 2³ = 121201543 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121201541) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 502791 + ... + 503031.

It is an arithmetic number, because the mean of its divisors is an integer number (4105530).

Almost surely, 2^121201551 is an apocalyptic number.

121201551 is a deficient number, since it is larger than the sum of its proper divisors (75863889).

121201551 is a wasteful number, since it uses less digits than its factorization.

121201551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 456 (or 453 counting only the distinct ones).

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

The square root of 121201551 is about 11009.1575972006. The cubic root of 121201551 is about 494.8832170170.

Adding to 121201551 its reverse (155102121), we get a palindrome (276303672).

The spelling of 121201551 in words is "one hundred twenty-one million, two hundred one thousand, five hundred fifty-one".