1955420621 has 24 divisors (see below), whose sum is σ = 2469075840. Its totient is φ = 1515840480.

The previous prime is 1955420617. The next prime is 1955420633. The reversal of 1955420621 is 1260245591.

It is a happy number.

It is not a de Polignac number, because 1955420621 - 2² = 1955420617 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1955420611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 161000 + ... + 172718.

It is an arithmetic number, because the mean of its divisors is an integer number (102878160).

Almost surely, 2^1955420621 is an apocalyptic number.

1955420621 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1955420621 is a deficient number, since it is larger than the sum of its proper divisors (513655219).

1955420621 is a wasteful number, since it uses less digits than its factorization.

1955420621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11945 (or 11934 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 35.

The square root of 1955420621 is about 44220.1381838637. The cubic root of 1955420621 is about 1250.4895407349.

The spelling of 1955420621 in words is "one billion, nine hundred fifty-five million, four hundred twenty thousand, six hundred twenty-one".